The correct answer is B. Chir and sal.
Chir and sal are both softwood trees. They are both members of the Pinaceae family, which also includes pines, firs, and spruces. Softwoods are characterized by their needle-like leaves and their relatively soft wood. They are often used in construction, furniture making, and papermaking.
Deodar and shishum are both hardwood trees. They are both members of the Meliaceae family, which also includes mahogany and rosewood. Hardwoods are characterized by their broad leaves and their relatively hard wood. They are often used in furniture making, flooring, and boatbuilding.
Sal and teak are both hardwood trees. They are both members of the Dipterocarpaceae family, which also includes meranti and keruing. Hardwoods are characterized by their broad leaves and their relatively hard wood. They are often used in furniture making, flooring, and boatbuilding.
Therefore, the only pair of trees in the question that both yield soft wood is chir and sal.