(a) ONCl=8+7+17=32e−ONO=8+7+8+1=24e− (correct)
(b)
Central O-atom is sp2-hybridised with 1 lone pair, so bent shape (correct).
(c) In solid state, ozone is violet-black. Ozone does not exist in solid state, thus incorrect.
(d) O3 has no unpaired electrons, so diamagnetic (correct). Hence, (c) is the correct.