Answer:
Option C
Step-by-step explanation:
Lichens can photosynthesize only because of the living algal partner, while Elysia chlorotica incorporates chloroplasts from algae into its cells.
Elysia chlorotica which is a form of sea slug feeds on a specie of the genus Vaucheria (an algae) and then retains only the chroloplasts of these algae which it uses for its own supply of energy.
The algal partner in lichens is the photosynthesizing partner. It produces food and this is its role in the relationship. The fungi are heterotrophs and cannot photosynthesize food. The fungi contribute to the relationship my absorbing mineral and water and presents it to the algae.