Solution:The pattern followed here is :(a, b, c) → {(a + c) ÷ 2}² = b
(21, 225, 9) → {(21 + 9) ÷ 2}² ⇒ (30 ÷ 2)² ⇒ 15² = 225
(12, 49, 2) → {(12 + 2) ÷ 2}² ⇒ (14 ÷ 2)² ⇒ 7² = 49
Similarly,
(14, 64, 2) → {(14 + 2) ÷ 2}² ⇒ (16 ÷ 2)² ⇒ 8² = 64
Hence, "(14, 64, 2)" is the correct answer.