Answer: Option A
Step-by-step explanation:
An endosperm is defined as the tissue which are produced inside the seeds during fertilization. As the endosperm surrounds the embryo, it acts as the food storage for the embryo and provide nutrition.
During embryo development , endosperms supports enlargement of cotyledons which helps in storage function and stores fats and starch and provide nourishment to the embryo.
for example cereal crops or grains are primarily endosperm which stores fat and starch and are edible fruits.
Hence, the correct option is A, endosperm can be a cotyledon which functions as a source of food for embryo.