From the given following sol how many can coagulate silicic acid sol? `Fe_2O_3C` starch, clay, `A_2S_3S` basic dye.

Explanation

To solve the question of how many of the given solutions can coagulate silicic acid sol, we need to follow a systematic approach.

### Step-by-Step Solution:

1. **Identify the Nature of Silicic Acid Sol**:
- Silicic acid sol is a colloidal solution that is typically negatively charged.

2. **List the Given Solutions**:
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