On mixing aqueous solution of copper sulphates with aqueous solution of ammonia a deep blue coloured solution is obtained. Choose the correct options :
A. The blue coloured solution shows presence of `Cu^(2+)` ions
B. The blue coloured solution does not show presence of `Cu^(2+)` ions
C. The blue coloured solution shows the presence of `[Cu(NH_(3))_(4)]^(2+)` ions
D. The blue coloured solution does not show the presence of `[Cu(NH_(3))_(4)]^(2+)` ions
