Desiccation adaptations help intertidal organisms to:

• A. Retain water through impermeable surfaces or mucous
• B. Avoid living in air at any time
• C. Resist freezing temperatures
• D. Rapidly desalinate tissues

Answer: (A)

When intertidal organisms are exposed to air during low tide, water can evaporate quickly. Desiccation adaptations help them keep as much water as possible, mainly by reducing evaporation through impermeable surfaces or by using a mucous coating to trap moisture on the body. This is why retaining water through impermeable surfaces or mucous is the best explanation for desiccation adaptations in these organisms.

Other options don’t fit because some intertidal species must tolerate air exposure rather than avoid it altogether; resisting freezing deals with temperature, not water loss; and rapidly desalinating tissues relates to salt balance, not preventing dehydration.