Which sentence is punctuated correctly?

AThe little boy proudly wrote the letters of his first name: C, H, A, and

Db. He showed the paper with his name on it to: his father, his cousin, and his sister.

CNext week he'll probably be ready to write the letters of his middle name J, O, E, and L.

DThe people he wants to show his paper to are: his mother, his brother, and his baby-sitter.