Which one of the following statements best reflects the idea behind the "Fractional Orbital Bombardment System" often talked about in media?

1. A

   A hypersonic missile is launched into space to counter the asteroid approaching the Earth and explode it in space.

   Hypersonic vs asteroid. Planetary defence, not FOBS.

2. B

   A spacecraft lands on another planet after making several orbital motions.

   Landing on another planet. Ordinary interplanetary flight.

3. C

   A missile is put into a stable orbit around the Earth and deorbits over a target on the Earth.

   A warhead placed in a fractional Earth orbit and deorbited onto a target. That is FOBS.

4. D

   A spacecraft moves along a comet with the same speed and places a probe on its surface.

   Comet rendezvous. Science mission, not bombardment.

Summary. Official key is (c). Fractional Orbital Bombardment System puts a payload into a partial Earth orbit and brings it down on a target — the path China tested in 2021 coverage. It is not asteroid defence, a planetary landing, or a comet probe.