A satellite S is moving in an elliptical orbit around the earth. The mass of the satellite is very small compared to the mass of earth

• A

  The acceleration of S is always directed towards the centre of the earth

• B

  The angular momentum of S about the centre of the earth changes in direction but its magnitude remains constant

• C

  The total mechanical energy of S varies periodically with time

• D

  The linear momentum of S remains constant in magnitude