In a hydropower plant, huge pipes that deliver water to the turbines are known as:

Correct option is C

Explanation:
In a hydropower plant, the penstock is a large pipe or conduit that:
· Carries water from the reservoir or intake structure down to the turbines in the powerhouse.
· Converts potential energy (due to height) into kinetic energy as water flows through.
· The pressure and velocity of water in the penstock is what spins the turbine blades, generating electricity.
Additional Information:
· Head is a measure of energy, not a physical structure.
· Reservoir stores water but does not deliver it directly to turbines.
· Spillway is for overflow and flood control, not energy generation.