Final answer:
The unit of measure to describe torque needed to tighten a small object is inch-pounds (in-lbs), which represents the torque applied when a one pound-force is exerted at a distance of one inch from the rotation axis.
Step-by-step explanation:
The unit of measure used to describe the torque needed to tighten a small object is d) Inch-pounds (in-lbs). Torque can be defined as the rotational equivalent of linear force. The SI unit of torque is newtons times meters (N·m), which represents the torque created by a one newton force applied at a distance of one meter from the rotation axis.
However, in this context, since we are referring to the tightening of a small object, which is commonly expressed in the US customary units, the correct answer is inch-pounds. Inch-pounds measure the torque when a one pound-force is applied at a distance of one inch from the pivot point.
It's important to distinguish this from pressure, measured in pounds per square inch (PSI), which is a unit of pressure. Other common units for pressure include newtons per square meter (N/m², or Pascal), kilopascals, and atmospheres, but these are not applicable for measuring torque.