Concept:All numbers in a group must follow the same property. Identify the group that contains a non-prime number.
Explanation:Check each group for prime numbers only.
Group A: 11, 13, 17, 19 → all primes.
Group B: 37, 41, 43, 47 → all primes.
Group C: 23, 29, 31, 33 → 33 is composite (3 × 11).
Group D: 2, 3, 5, 7 → all primes.
Only group C has a number that is not prime.
Answer:Option C (23, 29, 31, 33)