Many plant hormones show opposite effects. for example, the hormone present in the meristematic tissues of the shoots inhibits branching, whereas this effect is nullified by the hormones produced by roots. which are these two hormones respectively?
a) auxins and cytokinins
b) ethylene and abscisic acid
c) cytokinins and auxins

Option A,  Auxins and cytokinins

Explanation:

Both Auxin and cytokinin function opposite to each other. On one hand auxin is responsible for inhibiting the activation of axillary buds thereby causing branching in the  shoot system.  While on the other hand , the functioning of cytokinin is to promote cell division and make new plant organs in lower part of the plant body. It stimulate the process of branching in rootsystem.  

Hence, option A is correct

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