Explanation:

Velamen tissue is a specialized spongy tissue characterized by its ability to absorb moisture from the atmosphere:

- Option 1: Tap root - Primarily involved in absorbing water and nutrients from the soil, not in forming velamen.

- Option 2: Epiphytic root - This is correct as epiphytic roots, found in orchids and other epiphytic plants, have velamen to absorb moisture from the air.

- Option 3: Fibrous root - Typically seen in grasses for extensive soil anchorage and water absorption, not associated with velamen.

- Option 4: Respiratory root - Found in mangroves for gas exchange, not related to velamen formation.

Option 2 (Epiphytic root) is the correct choice