The correct option is
C X is a proton and Y is a neutron
In the first reaction, no of protons on LHS is
7+2=9; the no protons on RHS is
8Mass number on LHS is 14+4=18
Mass number on RHS is 17
Hence, the no of protons X will have is 9−8=1 and the no of neutrons X
has is 18−17=1
In the 2nd reaction, no of protons Y has is 4+2−6=0 and no of neutron Y has is 9+4−12=1
Hence, both X and Y have one neutron.
In case of X energy can be released equivalent of one neutron mass.
Hence, X is a proton and Y is a neutron.