answer="c"

The simplest way to improve your style is just to read more: the more literature we read the better our style. Like a process of photosynthesis it filters down through our consciousness enriching our thought processes and sharpening our use of words without us being aware that anything significant is happening. Get into the habit of reading well-written novels, so that you're always in the middle of reading one. Just fifteen to twenty minutes a night before you go to sleep will in time have a marked impact on your writing.

Beyond that there are certain guiding principles that will help you write light and interesting prose:

Brevity - economy and simplicity in your use of words and in your construction of sentences;

Logic - planning your essay so that you create a clear logical structure that can be followed easily;

Interest - changing the pace and rhythm of your writing, and using interesting examples and evidence to illustrate your arguments.