Auxins/cytokinins show the phenomenon of apical dominance.

Explanation

### Step-by-Step Solution:

1. **Understanding Apical Dominance**:
- Apical dominance is a phenomenon where the main central stem of a plant grows more vigorously than the side branches. This means that the growth of the lateral (side) buds is suppressed by the growth of the apical (top) bud.

2. **Role of Auxins**:
- Auxins are a type of plant hormone that promote stem elongation. They are primarily produced in the apical bud and are responsible for the growth of the plant upwards. When auxins are present in high concentrations at the apex, they stimulate the elongation of the stem and the formation of new apical buds.

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