The correct answer is C. Flexible modular outlet.
A flexible modular outlet is a type of outlet that maintains a constant discharge irrespective of fluctuation in the water levels of the supplying channel or water course. It is made up of a series of modules that can be easily connected and disconnected, allowing it to be adapted to different water levels. Flexible modular outlets are often used in irrigation systems, as they can provide a consistent flow of water to crops, even during periods of low rainfall.
A non-modular outlet is a type of outlet that is not made up of modules. It is typically made of a single piece of material, such as concrete or metal. Non-modular outlets are not as flexible as flexible modular outlets, and they may not be able to maintain a constant discharge during periods of low water levels.
A semi-modular outlet is a type of outlet that is made up of a few modules. It is not as flexible as a flexible modular outlet, but it is more flexible than a non-modular outlet. Semi-modular outlets are often used in applications where a constant discharge is not required, but where some flexibility is desired.
A right modular outlet is not a type of outlet. It is a typo. The correct answer is C. Flexible modular outlet.