Concept:HCF is the product of the smallest powers of all common prime factors in the given numbers.Explanation:For prime 3: exponents are 127, 128, 126. The smallest is 126.For prime 5: exponents are 121, 119, 120. The smallest is 119.For prime 7: exponents are 16, 21, 19. The smallest is 16.Thus, HCF = 3126×5119×716.Answer:C. 3126×5119×716