The correct option is D Self-pollinating plant variety showing inheritance of same traits for several generations
Plants that undergo self-fertilisation for several generations, such that their traits under consideration remain unchanged are known as true-breeding or pure breeding plants. It is one that when self-pollinated, produces offspring with the same traits. True-breeding plants are genetically identical for the character(s) being investigated. Pure breeds do not show variations and transmit the same traits for several generations upon self-pollination. Cross-pollination will usually not produce pure breeds, and might provide chances for a new or suppressed trait to be expressed in the offspring.