The correct answer is: Only III follows.
The statement says that it is important to develop oneself from within. This means that one should focus on their inner qualities, such as their character, values, and beliefs. It does not mean that one should not pay attention to their looks or appearances. In fact, it is important to take care of oneself both physically and mentally. However, one should not let their looks or appearances define them. They should focus on developing their inner qualities, which are more important in the long run.
Course of action I says that one should not pay attention to fashion. This is not a logical conclusion from the statement. The statement does not say that one should not pay attention to fashion. It simply says that it is important to develop oneself from within. One can do both of these things.
Course of action II says that one should pay attention to fashion. This is also not a logical conclusion from the statement. The statement does not say that one should pay attention to fashion. It simply says that it is important to develop oneself from within. One can do both of these things.
Course of action III says that books on self-development should be encouraged. This is a logical conclusion from the statement. The statement says that it is important to develop oneself from within. Books on self-development can help people to do this.
Therefore, the correct answer is: Only III follows.