The correct answer is: B. Diesel power plant.
A diesel power plant is a type of power plant that uses diesel fuel to generate electricity. It is a relatively simple and inexpensive type of power plant to install, and it can be used in a variety of applications, including backup power, remote power generation, and peak power.
A thermal power plant is a type of power plant that uses heat to generate electricity. The heat can come from a variety of sources, including coal, natural gas, oil, or nuclear fission. Thermal power plants are the most common type of power plant in the world.
A nuclear power plant is a type of power plant that uses nuclear fission to generate electricity. Nuclear power plants are very efficient at generating electricity, but they are also very expensive to build and operate.
A hydro-electric power plant is a type of power plant that uses the energy of moving water to generate electricity. Hydro-electric power plants are very efficient at generating electricity, and they are also very environmentally friendly. However, they can only be built in certain locations, such as near rivers or waterfalls.
In conclusion, a diesel power plant is the type of power plant that needs the least period for installation.