Question

Elise needs to revise her essay’s conclusion to use a more formal tone. Hera is a Greek goddess you should get to know. I like her because she’s strong, smart, and beautiful. Which revision of Elise's conclusion best uses a formal tone? Hera isn’t just an ordinary Greek goddess. She’s powerful because she’s beautiful, smart, and really strong. Readers should become familiar with the Greek goddess, Hera. Her strength, wisdom, and beauty set her apart from other Olympians. I think Hera is the greatest of the Greek goddesses. She’s not just beautiful, she’s also smart and strong. Everyone who reads about Hera knows that she is a beauty. She also has strength and wisdom to boot!

Answer 1

I believe it's that all readers should first and for most be familiar with the Greek Goddess herself, Hera. And of course how she stands out. Her strength, wisdom and beauty compared/ set apart from the other Olympians.

Answer 2

In order to improve her conclusion and make it more formal, I would say that the best option is Hera isn’t just an ordinary Greek goddess. She’s powerful because she’s beautiful, smart, and really strong (option A)
It is important to know that, except it is an option assay, the writer should not add personal information just justify the statements by providing factual support such as books, articles, etc. And in the conclusion, we do not have to include new info but paraphrase what was already discuss briefly. 

option B includes a "recommendation" which is not appropriated in this context. 
Option C expresses a personal opinion. 
Option D makes a generalization and it might be considered informal and vague.