Answer:
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.
Step-by-step explanation:
Formal tone can be defined as the tone which depicts the seriousness of the writer to the audience or the reader. This tone is not personal rather it's scholarly. The language used by the writer is with precision and impersonal.
From the given options, the statement that should be revised for a formal tone is the second one.
The tone is this sentence is informal and could be revised as 'Amaltheia, like a goat fed Zeus, for which he was really happy. Zeus was so much happy with Amaltheia that he turned her horn into the horn of plenty.
So, the correct answer is the second option.