The motion of planets is governed by Kapler's laws. (a) Kapler's second law, i.e., law of areas is equivalent to conservation of angular momentum. (b) Kapler's second law, i.e., law of areas is equivalent to conservation of linear momentum. (c) Cube of the time period of any planet is proportional to the square of the semi-major axis of its orbit. (d) Square of the time period of any planet is proportional to the cube of the semi-major axis of its orbit. Choose the most appropriate answer from the options given below :