Iron nail. the rest of those are not iron or some form of magnetic material.
Answer:

Explanation:
Given:
- mass of the object on a horizontal surface,

- coefficient of static friction,

- coefficient of kinetic friction,

- horizontal force on the object,

<u>Now the value of limiting frictional force offered by the contact surface tending to have a relative motion under the effect of force:</u>

where:
normal force of reaction acting on the body= weight of the body


As we know that the frictional force acting on the body is always in the opposite direction:
So, the frictional force will not be at its maximum and will be equal in magnitude to the applied external force and hence the body will not move.
so, the frictional force will be:

This is known as overextension! (the correct answer is B.)
Compressional waves can travel through all states of matter.
A plane mirror always forms a virtual image. the image and the object are the same distance from a flat mirror, the image size is the same as the object, and the image is upright!