Given below are two statements: 

Assertion (A): Cu is less reactive than hydrogen.
Reason (R):  Cu2+/ Cu is negative.
 
1. Both (A) and (R) are True and (R) is the correct explanation of (A).
2. Both (A) and (R) are True but (R) is not the correct explanation of (A).
3. (A) is True but (R) is False.
4. (A) is False but (R) is True.

Hint: E°Cu2+/ Cu value is positive.
Electrode potential of Cu2+ /Cu is + 0.34V and Electrode potential of H+ /H2 is 0.00 V.
Due to the positive value of Cu2+ /Cu, it loses an electron to H+ and reduces H+ into H2 . 
Cu is less reactive than hydrogen.
Hence, the Assertion is true but the reason is false.