IAA and zeatin exhibit similar influence on axillary shoot growth

Identify the correct pair of statements
(I) IAA and zeatin exhibit similar influence on axillary shoot growth
(II) N⁶ – furfuryl aminopurine and ethylene have opposite effects on leaf senescence
(III) Kinetin is not a natural substance
(IV) Gibberellins promote apical dominance
(a) (III), (IV)
(b) (II), (IV)
(c) (I), (IV)
(d) (II), (III)