Correct option is B
The main principle of prestressed concrete structures is to introduce compressive stresses in areas of the concrete member where tensile stresses are expected to develop under service loads.
Concrete is strong in compression but weak in tension, and cracks can develop in areas subjected to tensile stresses. By inducing compressive stresses (through pre-tensioning or post-tensioning), the tensile stresses due to applied loads are counteracted, reducing the likelihood of cracking and improving the structure's durability and load-carrying capacity.
