Student drivers are required to keep a log of their supervised driving hours. However, not all students are diligent in their record-keeping.
The transition that should be used to combine these sentences is the following one: however. This adverb is used to introduce a statement that contrasts with or appears to contradict something that has been previously said. In this case, you are saying that student drivers should keep a written record of their supervised driving hours yet you are also stating that not all of them do it thoroughly and well.
The correct answer would be C) or the third option.
Answer: D. One finds comfort in the familiar, even if the familiar is painful.
The answer to your question is D. The People!
Hope this helps you out! :)