Urea reacts with water to form A which will
decompose to form B. B when passed through
``\ce{Cu^{2+}(aq)}``, deep blue colour solution C is formed.
What is the formula of C from the following ?
(1) ``\ce{CuSO4}``
(2) ``\ce{[Cu(NH3)4]^{2+}}``
(3) ``\ce{Cu(OH)2}``
(4) ``\ce{CuCO3.Cu(OH)2}``