Why does social media trigger feelings of loneliness and inadequacy? Because instead of being real life, it is, for the most part, impression management, a way of marketing yourself, carefully choosing and filtering the pictures and words to put your best face forward.

        Online “friends” made through social media do not follow the normal psychological progression of an interpersonal relationship. You share neither physical time nor emotional conversations over the Internet. You simply communicate photographs and catchy posts to a diverse group of people whom you have “friended” or “followed” based on an accidental interaction. This is not to say that your social media friends can’t be real friends. They absolutely can, but the two are not synonymous. Generally speaking, there are no unfiltered comments or casually taken photos on our social media pages. And, rightfully so, because it wouldn’t feel safe to be completely authentic and vulnerable with some of our “friends” whom we don’t actually know or with whom trust has yet to be built.

        Social media can certainly be an escape from the daily grind, but we must be cautioned against the negative effects, such as addiction, on a person’s overall psychological well-being.

        As humans, we yearn for social connection. Scrolling (滚动) through pages of pictures and comments, however, does not provide the same degree of fulfillment as face to face interactions do. Also, we tend to idealize others’ lives and compare our downfalls to their greatest accomplishments, ending in feelings of loneliness and inadequacy.

        Social media can lead people on the unhealthy quest for perfection. Some people begin to attend certain events or travel to different places so that they can snap that “perfect” photo. They begin to seek validation through the number of people who “like” their posts. In order for it to play a psychologically healthy role in your social life, social media should supplement an already healthy social network. Pictures and posts should be byproducts of life’s treasured moments and fun times, not the planned and calculated image that one is putting out into cyberspace in an attempt to fill insecurities or unmet needs.

        Ultimately, social media has increased our ability to connect with various types of people all over the globe. It has opened doors for businesses and allowed us to stay connected to people whom we may not otherwise get to follow. However, social media should feel like a fun experience, not one that contributes to negative thoughts and feelings. If the latter is the case, increasing face to face time with trusted friends, and minimizing time scrolling online, will prove to be a reminder that your social network is much more rewarding than any “like”, “follow” or “share” can be.

解析：A。根据题干中的post comments selectively可定位到第二段第六句，其中selectively对应该句中的no unfiltered。该句指出，一般来说，社交媒体的网页上不会出现未经筛查的评论或随意拍摄的照片，也就是说人们在社交媒体上分享的内容是有选择性的。随后该段最后一句解释了人们这样做的原因：把自己完全真实而脆弱的一面展示在自己并不真正了解或有待建立信任的“朋友”面前，会让我们感到不安全。A项内容与此相符，其中not...all their online friends trustworthy（并不是所有网友都值得信任）对应定位句中的“friends” whom we don’t actually know or with whom trust has yet to be built（自己并不真正了解或有待建立信任的“朋友”），故A项为正确答案。

错项排除：原文中虽然讲到了人们在社交媒体上发布图片或评论前先要进行筛选，但并没有说到这是为了不冒犯其他人，故B项错误。C项中的lose their followers（失去关注者）和D项中的boost their popularity（增加关注度）在原文中没有提及，均可排除。