Identified A, B, C and D in the given figure of false fruit of apple.

False fruit are those fruits in which addition to ovary other floral parts (like thalamus) also contribute for its development is called false fruits. Examples– apple, pear, strawberry and cashew nut. In the given figure of false fruit (apple), the structure marked as A, B, C and D are respectively thalamus, seed, endocarp and mesocarp. Thalamus is a receptacle of a flower in which the embryo fruits and later the seeds are held. Seed is a fertilized and ripened ovule and the characteristics of gymnosperms and angiosperms. Endocarp is the innermost layer of the pericarp which surrounds a seed in a fruit. It may be membranous (as in apples) or woody (as in the stone of a peach or cherry). Mesocarp is the middle layer of the pericarp of a fruit, between the endocarp and the exocarp.