If autotrophs had not evolved on the primitive earth, then the heterotrophs would have probably have exhausted the:.a. amino acids. b. energy supply. c. oxygen supply d. carbon dioxide supply.

C. Oxygen supply

Explanation:

Autotrophs make their own food with carbon dioxide and create oxygen as a byproduct. Heterotrophs need oxygen to create energy and create carbon dioxide as a byproduct. Therefore, if there are no autotrophs, the carbon dioxide in the air won’t be able to be used to turn to oxygen, which heterotrophs need. The heterotrophs will use up all of the oxygen in the air, leaving lots of carbon dioxide behind. This is why we need plants and trees! Thus, the answer is C.

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