How do photoautotrophs make energy?

Select one:
a. They convert carbon dioxide, water, and inorganic compounds into carbohydrates.
b. They convert carbon dioxide, water, and organic molecules to carbohydrates.
c. They convert carbon dioxide, sunlight, and organic molecules to carbohydrates.
d. They convert carbon dioxide, water, and sunlight into carbohydrates.

I believe the answer is "B". Please correct me.