The answer is "I" , whenever it mentions doing something you use "I" when speaking about yourself.
The italicized word in the given sentence above is the name "Judy". In this sentence, "Judy" is used as the direct object. A direct object is a word or a noun which acts as the direct receiver of the action. "Judy" here receives the action "bought" done by the subject "Jane".
I think it’s A cause it can’t be C. Would be better to see the whole story maybe next time? Or a little bit more of it :)
