Why is the correct answer c?
i thought comma cannot be used to separate two independent clauses

The graph shows the populations of two species in a particular region over two decades. based on the graph, what can you conclude about the relationship between the two species? a. the two species have a parasitic relationship. b. the two species are mutualistic in nature. c. the two species exhibit commensalism. d. the two species have a prey-predator relationship. e. the two species have a familial relationship.

Rick is on a bicycle trip. every 4 days he bikes 230 km. if rick keeps this same pace for 16 days, how many kilometers will he bike?

D/dx(1+x^4+x^6/x^2+x+1) a)2x-1 b)2x+1 c)2 d)0