Who originally defined the sonnet form?
a. petrarch
b. ben jonson
c. john dunne
d. william shakespeare

Francesco Petrarch, is the right answer.

Explanation:

The sonnet was a form of poetry which originated at the Court of the  Frederick II, the Holy Roman Emperor in Palermo. Francesco Petrarch was one of the earliest people to actively using the sonnet form though he was not the one who discovered it. He used this form in his poetry and served as the inspiration for many other poets.