Concept: This question tests your understanding of adaptations in plants, specifically the specialized roots found in mangroves like Avicennia.

Why (A) is correct:

1. Assertion is true: Avicennia, a common mangrove plant, indeed possesses specialized roots called pneumatophores. These are negatively geotropic roots that grow upwards from the anaerobic soil.

2. Reason is true: Pneumatophores have small pores called lenticels on their surface. These lenticels facilitate the exchange of gases, allowing oxygen from the atmosphere to diffuse into the root system, which is otherwise submerged in oxygen-deficient (anaerobic) marshy soil. This oxygen is crucial for cellular respiration in the roots.

3. Reason is the correct explanation: The primary function of pneumatophores is to enable the plant to obtain oxygen for respiration in waterlogged, anaerobic environments. Thus, the reason directly explains why Avicennia has pneumatophores.

Common Mistake: Students might confuse pneumatophores with prop roots or stilt roots, which have different primary functions (support).

NEET Tip: Remember that pneumatophores are a classic example of an adaptation to physiological drought and anaerobic conditions found in mangroves. Look for terms like 'negatively geotropic' and 'lenticels' when identifying them.

Correct Answer: (A)