Presence of ______ discs is the characteristic feature of cardiac muscle.

Explanation

**Step-by-Step Solution:**

1. **Identify the Type of Muscle**: The question is asking about a specific feature that is characteristic of cardiac muscle. Cardiac muscle is one of the three types of muscle tissue in the body, the other two being skeletal and smooth muscle.

2. **Recall the Unique Features of Cardiac Muscle**: Cardiac muscle has several unique features that distinguish it from skeletal and smooth muscle. One of the most notable features is the presence of specialized structures that facilitate communication between cardiac muscle cells.

3. **Focus on Intercalated Discs**: The specialized structures that are unique to cardiac muscle are called intercalated discs. These discs are crucial for the function of the heart as they allow for synchronized contraction of the cardiac muscle cells.

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