2. Ba6.
Hola
OP said "for White".
Of ridiculous moves, Ke2 would clearly be the worst.
Of more reasonable moves that actually get played quite a bit, Bc4, f4 and b4 are all pretty bad. I'd probably nominate b4 as the worst.
My post #2.
1. e4 c5 2. Ba6 is the worst. It loses a piece.