What two nerves form the Sural nerve and what does it innervate?

a) Tibial and common fibular nerves; innervates the posterior calf and lateral foot
b) Median and ulnar nerves; innervates the forearm and hand
c) Femoral and sciatic nerves; innervates the thigh and leg
d) Radial and axillary nerves; innervates the arm and shoulder