The correct answer is: B. Underpinning
Underpinning is a technique used to support or strengthen the foundations of an existing structure by providing additional support underneath. This can be done by driving piles or piers into the ground, or by excavating and replacing the existing foundation material with stronger material.
Shoring is a temporary support system used to prevent the collapse of a structure that is in danger of falling. This can be done by using timber, steel, or concrete beams to support the structure from above.
Jacking is a technique used to lift or move a structure. This can be done by using hydraulic jacks, or by using cables or chains attached to cranes or other lifting equipment.
Piling is a technique used to support or strengthen the foundations of a structure by driving large, vertical rods into the ground. These rods are called piles, and they can be made of wood, steel, or concrete.