Starch molecules present in a maple tree are made from materials that originally entered the tree from the external environment as

Starch molecules present in maple tree from the external environment as INORGANIC COMPOUNDS.
Starch is made in the maple tree during the process of photosynthesis. The inorganic substances that are used during the process of photosynthesis are carbon dioxide and water; these two are mixed together in the presence of sunlight to form carbohydrates.

C) to ensure each new cell has an exact copy of the dna