The correct option is A Caryopsis
As their name indicates, pericarp of indehiscent fruits does not rupture on ripening and the seeds remain inside. Caryopsis is a dry single-seeded indehiscent fruit that differs from an achene in that the fruit wall is fused to the testa of the seed. It is the grain of cereals and grasses. Pod, follicle and lomentum are examples of dry dehiscent fruits where the pericarp ruptures to release the seeds.