How many oxygen atoms are present in 2 gram-atoms of $O$?

The correct option is A $12.044\times {10}^{23}$
1 gram atom of $O=6.022\times {10}^{23}$ atoms of $O$
So, 2 gram atoms of $O=2\times 6.022\times {10}^{23}$ atoms of $O$
$=12.044\times {10}^{23}$ atoms of $O$