The correct answer is: C. Three man stone pitching
Stone pitching is a method of protecting the water face of guide banks. It is done by laying a layer of stone on the face of the bank, with the stones overlapping each other. The stones are then held in place by a layer of mortar.
One man stone pitching is a method of stone pitching where one person lays the stones. This is the simplest and least expensive method of stone pitching, but it is not as effective as other methods.
Two man stone pitching is a method of stone pitching where two people lay the stones. This is a more effective method than one man stone pitching, but it is also more expensive.
Three man stone pitching is a method of stone pitching where three people lay the stones. This is the most effective method of stone pitching, but it is also the most expensive.
Four man stone pitching is not a common method of stone pitching. It is more expensive than three man stone pitching, but it is not as effective.