Which sentence has no errors in capitalization?

A.
"I try not to think about it," she said, "because it makes me sad."

B.
"I try not to think about it," She said, "because it makes me sad."

C.
"I try not to think about it," she said, "Because it makes me sad."

D.
"I try not to think about it," She said, "Because it makes me sad."