Which of the following is not an extrinsic factor affecting plant growth?

$A$ sleep movement in plants is a nastic response that occurs daily in response to

Which one of the plant growth regulators would you use if you are asked to:
$(a)$ Induce rooting in a twig
$(b)$ Quickly ripen a fruit
$(c)$ Delay leaf senescence
$(d)$ Induce growth in axillary buds
$(e)$ 'Bolt' a rosette plant
$(f)$ Induce immediate stomatal closure in leaves.

Essential oils are made of:

Factors which can modify geotropic responses are

Which one of the following pairs is not correctly matched?