Question #N1387

The process of photosynthesis involves a series of steps, each requiring energy, that result in the conversion of light energy into chemical energy that plants use to grow. Which of the following choices is the best way to punctuate the sentence?

The process of photosynthesis involves a series of steps, each requiring energy, that result in the conversion of light energy into chemical energy that plants use to grow.
A. The process of photosynthesis involves a series of steps, each requiring energy, that result in the conversion of light energy into chemical energy that plants use to grow.
B. The process of photosynthesis involves a series of steps, each requiring energy that result in the conversion of light energy into chemical energy that plants use to grow.
C. The process of photosynthesis involves a series of steps, each requiring energy, that result in the conversion of light energy into chemical energy that plants use to grow.
D. The process of photosynthesis involves a series of steps, each requiring energy that result in the conversion of light energy into chemical energy, that plants use to grow.