It seems that you have missed the given choices for this question, but anyway, the correct answer is FEMALE REINDEER. In 1944, reindeer were introduced to an optimal habitat on St. Matthew Island in the Bering Sea. The population grew exponentially until the winter of 1963-64, when the population dropped dramatically. The presence of FEMALE REINDEER may have helped maintain the population of reindeer.
I think that the correct answer is reactants of photosynthesis.
Glucose and Oxygen are the reactants
