Your chocie is absolutely correct. Please click the "report" button next time.

"Это" is the word that defines what an object is, "этот" / "эта" / "эти" are words that point to an object. For example (dialog):

-- Это велосипеды, выбирай себе любой, какой тебе нравится.

-- Я хочу этот велосипед.

Yes, it is.

Мне нравится этот стул. (нравится кто?/что?) Я люблю этот стул. (люблю кого?/что?)

yes it's in accusative form (inanimate masculine noun uses nominative https://www.duolingo.com/skill/ru/Accusative-Case%3A-the-direct-object/tips-and-notes).

нравится/нравятся = "like"
люблю = "to love [a person or pet]" or "to like [a thing or place or activity]" EXCEPT (according to olimo) "You can't use любить for something you try for the first time." A gift would be something you "try" for the first time, so you have to use нравится. "I like to eat borscht" could use люблю.
see: https://forum.duolingo.com/comment/11754722

But exception to the exception: Duo accepted Я не люблю этот стол, but might not accept я люблю этот стол - According to the Tips and Notes for the "Inf & Like" module https://www.duolingo.com/skill/ru/Infinitive%2C-Likes-and-Dislikes/tips-and-notes любить is preferred for negation of liking, as least for activities, and apparently for things.

I second this question. I was under the understanding that люблю was love and нравится was like

Мне is the Dative case form of Я.

With нравится/нравятся = "like", the person doing the liking is put in Dative case, which usually means, in the example of Мне, "to me". You may understand this better if you think of нравится/нравятся as "is pleasing", so the Мне нравится парк = "The park is pleasing to me", translated idiomatically to "I like the park."

Note that the thing which please "me" is in Nominative case, which means that it is actually the subject of the sentence. Мне is an indirect object.ц

See my comment responding above to avernie

стол is in nominative case. See my comment responding above to avernie