Well...this kind of question is...not sure how to say it but...answers may vary from different people. But I would go with A. Unusual
Because B? Dangerous? Yeah Mars is dangerous but saying it’s red doesn’t mean it’s dangerous. Saying Mars have dust storms would mean it’s dangerous. C. Different? That’s what I meant when I say answers may vary. Some people would choose this because earth is not red, and therefore, different. But I believe unusual is the best word here. D. Beautiful? Yeah that’s more like an opinion, no. E. Similar? Similar in what way? Earth isn’t red.
Infinitive is to keep. use is adverb. hope it helps.
In fact, they apply only to personal pronouns, possessive pronouns, and reflexive pronouns. It is only in these types, too, that gender differences are shown (personal he/she, possessive his/hers, reflexive himself/herself). ... Many of the pronouns listed above also belong to another word class - the class of determiners.
Pronouns @ The Internet Grammar of English - UCL
