Final answer:
The question deals with a tension force, which is the pulling force experienced by a material being stretched, such as ropes supporting a load. Therefore, the correct answer is (a) Tension force.
Step-by-step explanation:
The question refers to a situation where two angled ropes support a crate, and the ropes can withstand a maximum tension of 1500 N before they break.
In this context, the type of force being referred to is a tension force, which is a pulling force that acts along the length of a material when it is being stretched.
This is opposed to a compression force, which is a pushing force that compresses or shortens a material, a shear force, which acts perpendicular to the length of a material and can cause parts of it to slide past one another, and a normal force, which is perpendicular to the surface of contact and prevents objects from occupying the same space.
In the scenarios provided, the examples of tension in ropes and wires, the flexing of a pencil, and the adjustment in diameter of a steel wire due to weight, all involve physics concepts such as tension, stress, strain, and materials' mechanical properties.