`underset("Methyl bromide")(CH_(3)Br)underset(ether)overset(Na)tounderset([A])underset("Ethane")(CH_(3)-CH_(3))underset(hv)overset(Br_(2))tounderset([B])underset("Ethylbromide")(CH_(3)-CH_(2)-Br)underset("Ether")overset(Na)tounderset([C])underset("Butane")(CH_(3)-CH_(2)-CH_(2)-CH_(3))`