From the given following sol how many can coagulate the haemoglobin sol?
`FO_6 O_3 C` starch, clay, `A_2S_3 S` basic dye.

Explanation

To determine how many of the given sols can coagulate the hemoglobin sol, we need to analyze the charge of each sol and the charge of hemoglobin.

### Step-by-Step Solution:

1. **Identify the Charge of Hemoglobin Sol**:
- Hemoglobin sol is positively charged due to the presence of positively charged hemoglobin molecules.

2. **Determine the Requirement for Coagulation**:
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