Final answer:
After a rocket's fuel is expended, it usually separates from the spacecraft and falls to Earth, while the crew capsule employs a heat shield to safely re-enter the atmosphere.
Step-by-step explanation:
Once the rocket's fuel was used up, it typically separated from the rest of the spacecraft. For example, in the case of space shuttles, the solid fuel boosters were recovered and refueled after each flight, while the large liquid fuel tank was expended and did not return to Earth. The orbiter, which contained the crew and payload, would then use a heat shield to protect against high temperatures caused by atmospheric friction during re-entry. This is exemplified by the space shuttle's use of ceramic tiles as a heat shield. Therefore, in context with the options provided, the correct answer would be that the rocket separated from the capsule and fell to Earth (Option B).