$\mathop {Ph - OH}\limits_{(A)} ,\,\,\,\,\mathop {Ph - C{H_2} - OH}\limits_{(B)} ,\,\,\,\,\mathop {Ph - C{O_2}H}\limits_{(C)} ,\,\,\,\mathop {Ph - C{H_2}-\mathop N\limits^ \oplus {H_3}}\limits_{(D)} $
$(1)$ $C{H_3} - \mathop {CH}\limits^| - {C_2}{H_5}$
$(2)$ $C{H_2} = \,\mathop C\limits^| \, - \,\,C{H_3}$
$(3)$ $ CH_2 = CH -$
$(4)$ $(CH_3)_2 CH -$