Explanation

Pair the factors as a difference of squares. The first pair gives [(√2 + √3) + √5][(√2 + √3) − √5] = (√2 + √3)² − 5 = 2 + 3 + 2√6 − 5 = 2√6. The second pair gives 5 − (√2 − √3)² = 5 − (5 − 2√6) = 2√6. Multiplying the two results gives 2√6 × 2√6 = 4 × 6 = 24, option C.