Three identical spheres of mass M each are placed at the corners of an equilateral triangle of side 2 m. Taking one of the corner as the origin, the position vector of the centre of mass is
Options:
(a) `sqrt3(hati-hatj)`
(b) `hati/sqrt3+hatj`
(c) `(hati+hatj)/3`
(d) `hati+hatj/sqrt3`