Can someone explain that exercice?

it.lichess.org/training/66955
I don't understand the withe answer to your teorical best move
I would like to tell something more, but i leave you try it without spoilers

Black want to take pawn on e4.

We r already attacking e4 pawn 2 times but he has 2 defenders . So if we put more pressure on it he cant defend it anymore.

Yes i saw it too, but i don't played it cause usually in exercices you have to take more advantage than a pawn.
So you really just had to get a pawn?

Yea seems weird that in this puzzle you just gang up on a lowly pawn.

It takes two to tango. ( Battery)