Since the primary purpose of a topic sentence is to communicate the claim of the paragraph, it should be as concise as possible. Please select from the following topic sentence exemplars the one that is in line with this principle. 
A、 Poor diet and insufficient exercise results in this problem.
B、While sleep deprivation among high school students can be partially attributed to high levels of stress, which are particularly common in their final year of study, this issue is primarily rooted in poor diet and insufficient exercise.
C、While this may be one cause of the problem, it is primarily due to poor diet and insufficient exercise.