In what way does amensalism differ from commensalism?

A) In amensalism,only one species is affected by the other;in commensalism,both species affect each other.
B) In commensalism,only one species is affected by the other;in amensalism,both species affect each other.
C) In amensalism,the species that is affected by the other is negatively affected.In commensalism,the species that is affected by the other is positively affected.
D) In commensalism,the species that is affected by the other is negatively affected.In amensalism,the species that is affected by the other is positively affected.
E) British ecologists use the word "amensalism" and American ecologists use the word "commensalism" to describe the same phenomenon.