Assertion: The escape velocity for a planet is `v_e=sqrt(2gR)`. If the radius of the planet is four times, the escape velocity becomes half `(i.e. v_e'=(v_e)/2)`.
Reason: In the relation for escape velocity, `v_e =sqrt(2gR)`, the acceleration due to gravity `g` is inversely proportional to radius of the planet. Thus, `v_e prop 1/sqrtR`.
Options:
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false and R is also false.