What is the correct way to write sentences 9 and 10?

Responses
A Alex turned to look at, her dearest friend, and a smile curled up on her face.Alex turned to look at, her dearest friend, and a smile curled up on her face.
B Alex turned to look. At her dearest friend, and a smile curled up on her face.Alex turned to look. At her dearest friend, and a smile curled up on her face.
C Alex turned to look at her dearest friend, and a smile curled up on her face.Alex turned to look at her dearest friend, and a smile curled up on her face.
D Alex turned to look at her dearest friend and a smile curled up on her face.

C Alex turned to look at her dearest friend, and a smile curled up on her face.

The correct way to write sentences 9 and 10 is option D:

Alex turned to look at her dearest friend and a smile curled up on her face. (No punctuation is needed before "and" in this case.)