Detailed Explanation:

Mycorrhizal association is a symbiotic relationship between fungi and plant roots where the fungal hyphae increase root surface area for enhanced mineral absorption (especially phosphorus) and form a protective barrier against soil-borne pathogens.

✅ Option 4 – Correct: Increased mineral absorption and disease protection are the two primary advantages the plant receives from mycorrhizal fungi.
❌ Option 1 – Incomplete: Protection is only one of the benefits.
❌ Option 2 – Incorrect: The plant provides food (carbohydrates) to the fungus, not vice versa.
❌ Option 3 – Incorrect: Combines an incomplete and an incorrect option.