Perisperm is

Explanation:

• The term perisperm refers to a parenchymatous type of diploid tissue that is modified mainly to perform the function of storing food.
• The main composition of perisperm is starch and some fats, but proteins are absent.
• The functions of a perisperm are nearly similar to that of an endosperm.
• Perisperm is present in some seeds as a tissue that surrounds the embryo and the endosperm and is also known as the nutritive tissue.
• The perisperm is formed when the nucellus is not used up completely hence known as persistent nucellus or the remnant of the nucellus.

Final Answer: The correct answer is option D, that is, the perisperm is defined as the remnant of the nucellus.