Which of the following best improves sentence 10?

Direction:
The following passage is an early draft of an essay. Some parts of the passage need to be rewritten.
Read the passage and select the best answers for the questions that follow. Some questions are about particular sentences or parts of sentences and ask you to improve sentence structure or word choice. Other questions ask to consider organization and development. In choosing answers, follow the requirements of standard written English.

(1) The great advantage of early rising is the head start it gives us in our day’s work. (2) The early riser has done a large amount of hard work before other men even get out of bed.  (3) In the early morning, the mind is fresh, and there are few sounds or other distractions, so work done at that time is generally well done. (4) In many cases the early riser also finds time to take some exercise in the fresh morning air, and this exercise supplies him with a fund of energy that will last until the evening. (5) By beginning so early, he knows that he has plenty of time to thoroughly do all the work he can be expected to do and is not tempted to hurry over any part of it. (6) All his work being finished in good time, he has a long interval of rest in the evening before the timely hour when he goes to bed. (7) After a sound night’s rest he rises early next morning in good health and spirits for the labors of a new day. (8) He gets to sleep several hours before midnight at the time when sleep is most refreshing.

(9) It is very plain that such a life as his is far more conducive to health than that of the man who shortens his waking hours by rising late. (10) Who lies in bed late, if he wishes to do a full day’s work, goes on working to a corresponding late hour and denies himself the hour or two of evening exercise that he ought to take for the benefit of his health.