Assertion (A): In vertebrates, coelom is lined by peritoneum.
Reason (R): In vertebrates, coelom originates from endoderm.

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 both the assertion (A) and the reason (R) given in the statement.

### Step-by-Step Solution:

1. **Understanding the Assertion (A)**:
- The assertion states that "In vertebrates, coelom is lined by peritoneum."
- The coelom is indeed a body cavity in vertebrates that is lined by a membrane called the peritoneum. This statement is true.

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