Ammonia forms the complex `[Cu(NH_3)_4]^(2+)` with copper ions in alkaline solution but not in acid solution. The reasons for it is:

Options

A. In acidic solution , hydration protects `Cu^(2+)` ions
B. In acidic solution , proton co - ordinates with ammonia molecules to form `NH^(4+)` ions and `NH_3` molecules are not available
C. In alkaline solutions insoluble `Cu(OH)_2` is precipitated which is soluble in excess of any alkali
D. Copper hydroxide is amphoteric substance

Answer

B