Which of the following statement(s) is/are correct about self-incompatibility?

(i) It is a device to prevent inbreeding.

(ii) It provides a biochemical block to self-fertilization.

(iii) It ensures cross-fertilization.

(iv) It is governed by pollen-pistil interaction.

(v) It is governed by series of multiple alleles.

(vi) It prevents self-pollen (from the same flower of other flowers of the same plant) from fertilizing the ovules by inhibiting pollen germination of pollen tube growth in the pistil.