Which of the three answers are correct
A) Yes, they're related. They're both participles of the verb "to interest."
"Interested" is the past participle of the verb "to interest" and is often used as an adjective.
"Interesting" is the present participle of the verb "to interest" and is also often used as an adjective, albeit with different effect.
The adjectival difference between "interested" and "interesting" is "interested" describes one as having interest, one who something interests, whereas "interesting" describes what or who it is that elicits interest (i.e., What the interested person is interested in is what is interesting.)
B)Related yes, but with different meanings.
When talking about yourself or your feelings, use the –ed ending. “I am interested in music.” When talking about others or something outside yourself, use the –ing ending. “That music is interesting.”
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C)Putting aside the grammatical difference, the semantic difference is as follows: Interested is an adjective meaning "concerned, affected; having an interest, concern, or share in something.” Interesting is also an adjective but it means "arousing interest." Therefore, one is interested in something, and usually this thing will be interesting.
See this for interested and this for interesting
