Answer:
A
Step-by-step explanation:
The correct option would be A.
The presence of ammonia in the atmosphere of primitive earth provided the nitrogen found in the amine groups of amino acid and the nitrogenous bases in DNA. This has been proven through the simulation experiment of the primitive earth's atmosphere by Stanley Miller and Harold Urey.
The water in the primitive atmosphere was formed from the condensation of water vapour from volcanoes that were characterics of the earth's environment while oxygen in itself is not needed for photosynthesis but a by-product of it.