Explanation

5²ⁿ − 1 = 25ⁿ − 1 is always divisible by 25 − 1 = 24. The number 24 has exactly 8 natural-number divisors: 1, 2, 3, 4, 6, 8, 12, 24. So the expression is always divisible by a minimum of eight natural numbers. Hence option D.