The correct option is B has
It is to be kept in mind that Either, Neither, Each, Everyone, Many a, must be followed by a singular verb.
'Either of the martyr-widows' means each individual martyr-widow. So, we are referring to a singular noun. By the general convention, a singular noun takes a singular verb. Hence, Option A 'has' is correct and Option B 'have' is incorrect.
Options C and D are incorrect as they are irrelevant to the context.