My eldest sister started working as a freelance journalist as soon as

A. No sooner had my eldest sister started working as a freelance journalist than she graduated from university.

B. Hardly had my eldest started working as a freelance journalist when she graduated from university.

C. No sooner had my eldest sister graduated from university than she started working as a freelance journalist.

D. After my eldest sister graduated from university, she had started working as a freelance journalist.