A Researcher Wants to Find Out Whether Campers Prefer Cotton

Multiple Choice

A researcher wants to find out whether campers prefer cotton or nylon sleeping bags.A troop of boy campers tried cotton and a troop of girl campers tried nylon sleeping bags.The sleeping bags were rated for softness and warmth.The confounding variable is

A) cotton or nylon material.
B) softness.
C) gender of camper.
D) campsite.