Ok, if we omit "It" in "It sounds fine", then it should be written as "Sounds fine" or "Sound fine"? [closed]

Question

Here is a conversation in an English material.

A: You should take part in  a music club
B: Sounds fine

I am not sure "Sounds fine" is a correct writing way. I feel that it should be "Sound fine"

So "Sounds fine" or "Sound fine", which one is correct?

Answer 1

A: You should join a music club
B: Sounds fine.

That is an abbreviation. In full we have:

A: You should join a music club.
B: That sounds fine.

or

A: You should join a music club.
B: That idea sounds fine.

Whichever way you look at it, the verb should be 3rd person singular.