Answer: A spanner with a long handle
Explanation: The use of a spanner for opening the nut of a simple machine will employ the principle of moment.
The force apply to the nut is considered as load while the force applied to the spanner is considered to be effort.
Before the nut can be opened, the effort must overcome the load.
Since moment is the product of a force and the perpendicular distance, the spanner with a long handle will produce a higher moment.
Therefore, a spanner with a long handle will be preferred.