DENDROLOGY

Detailed explanation-1: -Seeds need oxygen so that they can produce energy for germination and growth. The embryo gets energy by breaking down its food stores. Like all organisms, this is done through a process known as aerobic respiration.-a series of reactions where energy is released from glucose, using oxygen.

Detailed explanation-2: -Seeds have stored energy in the form of starch which feeds them until the leaves can begin the process of photosynthesis. In some ways they can be compared to batteries, holding energy until it is needed. Seed size and planting depth impact the process of germination because they affect the seeds energy stores.

Detailed explanation-3: -So the correct option is ‘Heat’.