What is the gravitational field and the potential at the centroid of an equilateral triangle formed by three mass points, each of mass 'm' and placed at the vertices of the triangle with side length 'l'?

A) Gravitational field: Gm/l^2
Potential: -3Gm/2l
​B) Gravitational field: Gm/2l^2
Potential: -Gm/l
C) Gravitational field: 2Gm/l^2
Potential: -2Gm/l
D) Gravitational field: 3Gm/l^2
Potential: -Gm/2l