Which of the following statements are true ?
(A) A force can act on an object with or without being in contact with it
(B) Earth's molten metallic core is the origin of the magnetic field
(C) Gravitational forces is one of the strongest forces
(D) Nuclear forces are weakest of fundamental forces
1
(A) and (D)
2
(B) and (C)
3
(C) and (D)
4
(A) and (B)