Which of the following is true for auxin?

i) They help to prevent fruit and leaf drop at early stages but promote the abscission of older mature leaves and fruits.

ii) Auxins prevent apical dominances and it is applied in tea plantations, hedge-making.

 iii) N A A (naphthalene acetic acid) and 2, 4-D (2, 4-dichlorophenoxyacetic acid) are synthetic auxins.

 iv) Auxins also induce parthenocarpy, e.g., in tomatoes.

v) 2, 4-D, widely used monocotyledonous herbicide.

 vi) 2, 4-D is used to prepare weed-free lawns by gardeners.

vii) Auxin also controls xylem differentiation and helps in cell division.