Online classes began to be popularized just a few decades ago. They are advertised as a way for adults to finish their education and students to learn the material at their own pace—it is far more compatible for people with busy schedules.

        But after being enrolled in an online course last fall semester, I came to realize online classes were merely a means to fulfil course requirements.

         First of all, students lack the desire to learn, and they simply complete their assignments to receive credit for a passing grade rather than genuinely engage with the course material.

        As online courses tend to have more than 100 students, most of the assignments are short and simple. They are not designed for students to interact with the material in depth but designed to be graded easily to accommodate such a large number of students.

         Perhaps the biggest disadvantage of taking an online class is the absence of face-to-face interaction between the teacher and their students. Live sessions are infrequent and are often scheduled during the middle of the day when students have to attend other classes or work. The office hours of the professor may also be during inconvenient times for many students as well. Most interaction with the professor has to be through email which is often impersonal. It is nearly impossible for students to build a relationship with their professor.

        There is also little interaction amongst students. It can be harder for students to create study groups and form relationships with their peers.

        Online classes also require either a computer or laptop and a reliable internet connection. Not all students have access to these types of resources, whether it is for financial or other reasons, and some students can be put at a disadvantage.

        Offering online classes certainly helps students who would otherwise not be able to attend classroom sessions. However, they fail to provide a genuine education with an emphasis on convenience rather than critical thinking. We need restructured online classes in which students can have a learning experience that will actually provide quality education.

解析：D。根据题干中的genuine education可定位至最后一段第二句。该句提到，在线课程无法提供一种真正的教育（a genuine education），因为它只是强调便捷性而不注重批判性思维的培养。也就是说在作者眼里，真正的教育应该把重点放在批判性思维上。D项与此内容相符，其中的analytical thinking ability对应句中的critical thinking，故为正确答案。 

错项排除：A项的useful knowledge、B项的Training of real-life skills和C项的students’ personalities在原文中都无依据，故均可排除。