$ Mangrove plants grow in the deserts.
! These plants have symbiotic mycorrhizal roots.

Options

A. If both As and R are correct and R is correct explanation of As
B. If both As and R are correct but R is not correct explanation of As
C. If As is correct, R is wrong
D. If both As and R are wrong.

Answer

**Step-by-Step Text Solution:**

1. **Understanding the Assertion**: The assertion states that "Mangrove plants grow in the deserts." This is incorrect. Mangrove plants are typically found in coastal areas, particularly in muddy or marshy soils near estuaries and tidal zones, not in deserts.

2. **Understanding the Reason**: The reason given is that "these plants have symbiotic mycorrhizal roots." While many plants do have mycorrhizal associations that help them absorb nutrients, mangrove plants are characterized by a different type of root structure known as pneumatophores.

3. **Identifying the Correct Root Structure**: Pneumatophores are specialized aerial roots that extend above the water or soil surface. They are adapted for gas exchange, allowing the plant to take in oxygen in waterlogged conditions, which is typical of mangrove habitats.

4. **Conclusion**: Since both the assertion (that mangrove plants grow in deserts) and the reason (that they have symbiotic mycorrhizal roots) are incorrect, we conclude that both statements are false.

**Final Answer**: Both the assertion and the reason are wrong.

---