Choose the correct alternative
(a)Acceleration due to gravity increase/decrease with increasing altitude.
(b) Acceleration due to gravity increase/decrease with increasing depth (assume the earth to be a sphere of uniform density).
(c ) Acceleration due to gravity is independent of mass of the earth/mass of the body.
(d) The formula `- GM m ((1)/(r_(2)) - (1)/(r_(1)))` is more/less accurate than the formula `mg (r_(2) - r_(1))` for the difference of potential energy between two points `r_(2)` and `r_(1)` distance away from the centre of earth.