(c)the Chairman or any officer of the Municipality, as the case may be, a written document signed,-(i)in the cases referred to in clause (a), by the [Chairman] [Substituted by the West Bengal Act XLV of 1994, s. 23, w.e.f. 10.10.1994 for'Municipal Secretary'.], and(ii)in the cases referred to in clause (b) or clause (c), by the Chairman or such officer of the Municipality, purporting to convey or set forth such approval, sanction, consent, concurrence, declaration, opinion or satisfaction, shall be sufficient evidence thereof.