Select the most appropriate indirect form of the given sentence.
Granny said to Nina, “I don’t know why you think it is so wonderful.”

A

Granny said to Nina that she hadn’t known why she was thinking it was so wonderful.

B

Granny said to Nina that I don’t know why you think it is so wonderful

C

Granny said to Nina that she didn’t know why she thought it was so wonderful.

D

Granny said to Nina that she doesn’t know why she thinks it was so wonderful.