A Perfectly Competitive Industry Has 10 Firms, Each with an MC

A perfectly competitive industry has 10 firms, each with an MC curve that can be expressed as MC = 5q, where q is the level of output for each firm. The minimum point of the AVC curve is $5. Which of the following equations would describe upward-sloping portion of the industry supply curve for the industry, where Q is the market quantity and P is the market price?

A) P = Q for Q $\ge$ 10
B) P = 0.5Q for Q $\ge$ 10
C) P = 2Q for Q $\ge$ 10
D) P = Q for Q $\ge$ 20