Option (C) 25 cm
Perimeter of sector = 2r + arc length = $2(7) + \dfrac{90}{360} \times 2 \times \dfrac{22}{7} \times 7 = 14 + 11 = **25$ cm**.
Perimeter of a sector includes two radii + arc length (not just the arc). Students often forget to add the two radii. Here: arc = ¼ × 2π × 7 = 11 cm; adding 2 × 7 = 14 cm gives 25 cm. Option D is the answer.