The types of organisms you would expect to see in an area that recently experienced a volcanic eruption.
a. trees
b. mosses and algae
c. grass and bushes
d. all types of organisms in fewer numbers

The organism that we could expect in area near volcanic eruption is: B. Mossess and ALgae
After volcanic eruption, land composition will be damaged to the point where normal trees/grass wouldn't be able to grow on it. This damage on the other hand, created a nutrient composition that is perfect for Mossess and Algae to live in.

The answer is mosses and algae. Since nothing else can really grown due to the lava burning everything to the ground, including the seeds and the moss and algae can grown in a variety of different areas.