Judge the following sentence according to the criteria given below: Great abundances of benthic life ...

Judge the following sentence according to the criteria given below: Great abundances of benthic life are found beneath areas of high primary productivity BECAUSE life on the ocean floor mostly depends on the productivity of the ocean's surface waters
 
  A) The assertion and the reason are both correct, and the reason is valid.
  B) The assertion and the reason are both correct, but the reason is invalid.
  C) The assertion is correct, but the reason is incorrect.
  D) The assertion is incorrect, but the reason is correct.
  E) Both the assertion and the reason are incorrect.