The statement that should be revised for a more formal tone is option B: Amaltheia was kind of like a goat who fed Zeus, which Zeus was really happy about. In fact, he turned the goat’s horn into the horn of plenty.
The words kind of like are words of a low register, as such it conveys a very informal message that could be delivered by any teenager.
A formal tone should implement high register and more sophisticated words, avoid colloquial, informal words and contractions.
