"Scissor gait" is a condition in which one limb crosses in front of the other during stepping as a result of powerful hip adduction caused by continuous, unwanted nerve activity. Overactivity of which of the nerves can cause this condition?

With "scissor gate" there is overactive adduction of the thigh. So, you need to identify which nerve innervates the adductor compament. And that nerve is the obturator nerve. The obturator nerve innervates the medial compament of the thigh, including adductor longus, magnus, and brevis. If the obturator nerve was firing too much, the leg would be constantly adducting, causing the scissor gait. The femoral nerve innervates the quadriceps muscles, which extend the leg at the knee. The inferior gluteal nerve innervates gluteus maximus, which is impoant for powerful extension of the thigh. The tibial nerve innervates the hamstrings, which flex the knee and extend the thigh. The tibial nerve also innervates the muscles of the posterior compament of the leg, which plantarflex the foot.