DIRECTIONS: Read the passage(s) given below and answer the questions that follow Passage - 3 If in a closed room there is some material that is burning, you may have felt suffocation. This is due to excess carbon dioxide that may be accumulating in the room. Plants and animals consume oxygen for respiration and produce carbon dioxide. Assertion (A): Oxygen helps in burning of substances. Reason (R): Burning of substances is a combustion process.

• A. Both A and R are true and R is the correct explanation of A.
• B. Both A and R are true but R is not the correct explanation of A.
• C. A is true but R is false.
• D. A is false but R is true.