Br has a low reactivity in $CH_2 =CH-Br$ because (i) of -M effect of bromine (ii) of more electro negativity of bromine (iii) of partial double bond character between $C-Br$ bond. (iv) of the +M effect of bromine.

Question

$(a)\;(i)\; and\;(ii) \\ (b) \; (ii)\;and \;(iii) \\ (c) \;(ii)\;and \;(iv) \\ (d)\;(iii)\;and (iv)$