Question

which word means no oxygen? anaerobic no air air aerobic

Explanation:

To determine the word meaning "no oxygen", we analyze each option:

• "anaerobic": The prefix "an - " means "without" and "aer" relates to air/oxygen, so "anaerobic" means without oxygen.
• "no air": This is a phrase, not a single word, and "air" is broader than just oxygen.
• "air": Refers to the gaseous mixture, not "no oxygen".
• "aerobic": Means with oxygen (from "aer" for air/oxygen and the suffix indicating presence).

So "anaerobic" is the correct term.

Answer:

A. anaerobic