Green grass it uses for comouflaquae turns brown to drought
Absence of oxygen means anaerobic respiration ; which has 2 different pathways.
First Pathway ; Alcoholic fermentation which takes place in yeast.
Pyruvate is decarboxylated into ethanal releasing co2 as waste product.
Ethanal is toxic , so its reduced by help of NADH to ethanol in presence of alcohol dehydrogenase enzyme , and Free NAD is released to continue glycolysis.
2) The second pathway is Lactic fermentation which takes place in mammalian muscles.
Pyruvate accepts hydrogen and is converted to lactate by the help of enzyme lactate dehydrogenase , again free NAD is released to continue glycolysis.
Hope I made it clear enough :)
I think the answer would be A , break the darkness period with a flash of light for some time so that the plants can bloom all year round.