The force of gravitation is

The correct option is Conservative.

To understand why the force of gravitation is conservative, let us look at the definition of a conservative force and its key properties:
1. Work Done is Path-Independent: A force is said to be conservative if the work done by or against the force in moving a particle between two points depends only on the initial and final positions of the particle, and is completely independent of the path taken between them.
2. Work Done in a Closed Loop is Zero: The net work done by a conservative force on a particle moving along any closed path (returning to its starting position) is zero.

Mathematically, the gravitational force $F$ between two masses $m_1$ and $m_2$ separated by a distance $r$ is given by Newton's law of universal gravitation:
$F=-\frac{G{m}_1{m}_2}{r^2}\hat{r}$
Because the gravitational force can be expressed as the negative gradient of a potential energy function $U\left(r\right)=-\frac{G{m}_1{m}_2}{r}$, it is mathematically guaranteed to be a conservative force.

Let's briefly evaluate the other options:
- Repulsive: Gravitational force is always attractive in nature, never repulsive.
- Electrostatic: Electrostatic force is the force between charges, whereas gravitational force acts between masses.
- Non-conservative: Non-conservative forces (like friction or air resistance) dissipate energy and depend on the path taken, which is not true for gravity.