At the sink , osmotic pressure must be _______

Explanation

**Step-by-Step Solution:**

1. **Understanding the Concept of Osmotic Pressure:**
- Osmotic pressure is the pressure required to prevent the flow of solvent molecules through a semi-permeable membrane from a region of lower solute concentration to a region of higher solute concentration. It is a measure of the tendency of water to move into a solution.

2. **Identifying the Sink:**
- In the context of plants, a "sink" refers to a part of the plant where substances (like sugars) are being used or stored. Common sinks include roots, fruits, and growing tissues.

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