The correct answer is: D. Symbiotic association between a fungus and roots of higher plants.
Mycorrhiza is a symbiotic association between a fungus and the roots of a vascular plant. The fungus helps the plant to absorb water and nutrients from the soil, while the plant provides the fungus with carbohydrates. Mycorrhizae are found in almost all plant species, and they are essential for the growth and survival of many plants.
Option A is incorrect because liverworts are non-vascular plants. Mycorrhizae are only found in vascular plants.
Option B is incorrect because algae are photosynthetic organisms. Mycorrhizae are not parasitic on algae.
Option C is incorrect because mycorrhizae are not parasitic on roots of plants. They are a symbiotic relationship.
I hope this helps! Let me know if you have any other questions.