Why Qd1 is the best move? As per subject, why Qd1 is the best move and all other moves for queen like Qd2 and Qd3 are not? I understand that it’s important to cover d column but why 1 and not 2 or 3?

Also why Rd1 is not a good move?
Qd1 hits the bishop on d6 and the knight on h5. One of those will be won.

Btw, I think this a famous game between Larry Christiansen and Anatoly Karpov. Famous, of course for this early blunder. Here, you can see the whole game and maybe find out more about the players.