Find the one which does not belong to that group ?
Answer: B
36 = 6⊃2;, 49 = 7⊃2;, 64 = 8⊃2;, 81 = 9⊃2; and 100 = 10⊃2;.
36, 64, 81 and 100 are squares of composite numbers, but not 49.