Use the Following Information and Figure to Answer the Question

Multiple Choice

Use the following information and figure to answer the question.
The sea slug Pteraeolidia ianthina (P. ianthina) can harbor living dinoflagellates (photosynthetic protists) in its skin. These endosymbiotic dinoflagellates reproduce quickly enough to maintain their populations. Low populations of the dinoflagellates do not affect the sea slugs very much, but high populations (> 5 x 10⁵ cells/mg of sea slug protein) can promote sea slug survival.

Percent of sea slug respiratory carbon demand provided by indwelling dinoflagellates.
Which of the following would be a potential disadvantage to the sea slugs of housing the dinoflagellates?

A) The CO₂ produced by the dinoflagellates would poison the sea slug.
B) The dinoflagellates would be an energy drain on the sea slug.
C) The sea slugs are exposed to predators when they spend time in the sunlit areas needed by the dinoflagellates.
D) The dinoflagellates will reduce the ability of the sea slugs to move.