Which answer most clearly explains a key message of "helen grey"?

The correct answer is “have more than beauty to offer others.”

The answer that most clearly explains a key message of “Helen Gray” is: Have more than beauty to offer others.

In parts of the poem, the author writes: “Because you are handsome, is that a reason to be proud?”, meaning that there should be more aspects than beauty for a person to feel proud. In other excerpt, the author writes: “But so you miss that modern charm”, meaning that modesty and humility are important characteristics in a person.

Helen Gray is a poem written by Christina Georgina Rossetti.  

The other options were, a) be careful of what others think of you, b) make sure to be nice to others, abn c) give more of yourself to those in need.

taking into account that a theme is the central topic a text treats and can be developed through a story, play, poem etc. the following are themes that can be further developed:  

my best friend jeffrey has many unusual interests. (the story could be about each of the unususal interests)

once a man gives his soul over to evil, he can never go back. (this could be a saying or a proverb)

the three sheepdogs lay around the yard all day. (it could be developed detailing how each of these sheepdogs lay around)

a priest's collar has an unusual effect upon people. (it could be developed detailing the different effect upon people)

innocence is a powerful force in a world full of corruption. (it could be developed detailing how is a world full of corruption)

king lear is a play shakespeare wrote later. (it is just a sentence and doesnt give any idea or topic to be discussed in details.

evil often wears the disguise of innocence. (this could be a saying or a proverb)

the bottom of the ocean