Which among the following is an ‘action-at-a-distance’ force?

Gravitation

The correct answer is option 3. Gravitation.

Among the following options, the 'action-at-a-distance' force is Gravitation.

Gravitation is an example of an 'action-at-a-distance' force because it acts between two objects without the need for physical contact between them. It is the force of attraction that exists between any two objects with mass. According to Newton's law of universal gravitation, every mass in the universe attracts every other mass with a force proportional to the product of their masses and inversely proportional to the square of the distance between their centers. This force of attraction acts instantaneously across space, without the need for intermediary objects or direct contact between the masses involved.