For the following Assertion and Reason, the correct option is
Assertion (A) : When Cu (II) and sulphide ions are mixed, they react together extremely quickly to give a solid.
Reason (R) : The equilibrium constant of Cu2+ (aq) + S2- (aq) ⇌ CuS(s) is high because the solubility product is low.
(1) Both (A) and (R) are true and (R) is the explanation for (A)
(2) Both (A) and (R) are false
(3) (A) is false and (R) is true
(4) Both (A) and (R) are true but (R) is not the explanation for (A)