Assertion (A): The endoskeleton of animals is totally composed of living tissues.
Reason (R): Bone and cartilage are living tissues.

Options

A. Both A and R are true and R is the correct explanation for A.
B. Both A and R are true but R is not the correct explanation for A.
C. A is true and R is false.
D. A is false and R is true.

Explanation

To solve the question, we need to analyze the assertion and reason provided.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "The endoskeleton of animals is totally composed of living tissues."
- This statement is **incorrect** because while the endoskeleton includes living tissues (like bones and cartilage), it also contains non-living components (like calcium phosphate).

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