Rocket propulsion basics: A rocket engine carries its own oxidizer; combustion does not use atmospheric air.

Introduction / Context:
Rocket engines operate in near-vacuum and outer space, so they cannot depend on atmospheric oxygen. This question checks the basic concept of how rockets burn fuel independent of the environment.

Given Data / Assumptions:

• Chemical rocket with propellants stored onboard.
• Combustion chamber and nozzle expel high velocity gases to produce thrust.
• No reliance on ambient oxygen, unlike air-breathing engines.

Concept / Approach:
Rocket propellants are divided into fuel and oxidizer. The oxidizer supplies the oxygen needed for combustion. Options include liquid oxygen, nitrogen tetroxide, or solid oxidizers in composite propellants. Because the oxidizer is onboard, rockets function both within the atmosphere and in space.

Step-by-Step Solution:

Verification / Alternative check:
Historical missions (orbital and deep space) use liquid oxygen or storable oxidizers. Ground tests also show rocket operation in evacuated chambers, reinforcing the independence from air.

Why Other Options Are Wrong:

• Surrounding air / compressed atmospheric air: Applicable to air-breathing engines, not rockets.
• None of these: Incorrect because rockets explicitly carry oxidizer.

Common Pitfalls:
Confusing rockets with jet engines. Jets compress atmospheric air; rockets do not ingest air for combustion.

Final Answer:
its own oxygen