How does Nf1 then black plays Nxd4 work out. If NxN then exd4 and Black may be able to liquidate with an eventual d5?!

Here are the improvements I see for White:

Nf1 (this prepares for a hop to g3, and possibly f5; it opens the diagonal for my c-Bishop; and it allows my Q to give added protection to the D-pawn)

d5 (locks down his e-Bishop and his Q)

After moving the N on d2, then Be3

a3, then b4, then Bb2 (this prevents his N from posting on b4)

b3, then Bb2 (this prevents his N from posting on c4; but if he moves a5, he might be able to open the a-file for his R)

Among the choices, I would select Nf1.