Who cares? You've got a bunch of noobs spewing out random answers. In no way does it make it the best opening.
Against 1.e4, the moves 1...e5, 1...e6, 1...c5, and 1...c6 are equally playable, and the best one depends on each person's playing style. The best for one is not the best for someone else. The other 16 moves by Black are inferior, but if one says they prefer 1...e5 and another 1...c5 while I prefer 1...e6, I will not argue with them, because no one opening is "best" and so this whole thread is a waste of chess.com storage space!
(as white) 1.d4 2. Nf3 & 3. e3 too many possible replies to list after.
(as black) 1...d4 .... doesn't matter what white plays
Oh, it does matter what White plays.
1...d5 is only sound against 19 of White's 20 legal moves. It is no good against 1.c4.