x, y and z are three integers. We need to find if they are consecutive integers.
From statement I alone, z – x = 2. There is no information about y.
If z = 3 and x = 1 along with y = 2, x, y and z are three consecutive integers.
If z = 4 and x = 2 along with y = 1, x, y and z are NOT consecutive integers.
Statement I alone is insufficient. Answer options A and D can be eliminated.
From statement II alone, x<y<z. This is insufficient to find out if x, y and x are consecutive integers.
Statement II alone is insufficient. Answer option B can be eliminated.
Combining statements I and II, we have the following:
From statement II, x<y<z; from statement II alone, z – x = 2.
This is possible only if all the three integers are consecutive integers.
The combination of statements is sufficient. Answer option E can be eliminated.
The correct answer option is C
Hope that helps!
Aravind BT