A spaceship t travels through empty space. There are no gravitating bodies Captain wants to change course A. It's possible only using the rocket effect. B. It's only necessary to rotate external propellers until it enters a gravitational force The Captain is out of luck. The ship will coast field, or at least until it is surrounded by some gas

A) It is possible using the rockets

Explanation:

Spaceships don't have propellers, those require a fluid medium to work, and there is none in the vacuum of space.

Rocket thrusters do not require any fluid medium or being surrounded by any gas to work. Rockets work by the principle of conservation of momentum, they expell some propellant mass backwards at a high speed. In order to conserve momentum in the rocket-propellant system, the rocket increses it's speed forwars.