The correct option is D Ethyl propionate
Option D is the correct answer.
The general reaction between ether and CO is
R−O−R+COBF3, 500 atm−−−−−−−−→150°CR−CO−O−R
By that logic, the given reaction should yield
C2H5−O−C2H5+COBF3, 500 atm−−−−−−−−→150°CC2H5CO−O−C2H5 i.e. Ethyl propionate.