22. If plants are kept in the dark, they have elongated internodes, making them spindly. This effect is due to:
(A)an overproduction of auxin.
(B) phytochrome in the Pr form.
(C)phytochrome in the Pfr form.
(D)an overproduction of gibberellins.
(E)a lower auxin/cytokinin ratio in the stems.

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