Answer:
Commensalism
Step-by-step explanation:
Lava lizards and the sea lion has a symbiotic relationship called commensalism.
When Sea lion take a nap, they attract flies and lava lizards feed on those flies and the sea lions apparently get rid of flies. In this act, flies does not harm sea lion and lava lizard get benefit.
Commensalism is defined as a symbiotic relationship between two organism in which one organism get benefit from other organism while causes no harm to the second organism.
Hence, the correct answer is "Commensalism".