GMAT 80里的一道题目

Movie pirating,the illegal videotaping of a new theater release and
subsequent selling of the tape on the balck market,is a major concern
to the film studios that produce today's mainstream movies.

  when pirating sales are high,individual studios whose movies are being
taped and sold illegally lose a large amount of revenue from the
black-market viewer who would otherwise pay the full price.

  A low level of pirating sales during a specific period,however, is
a fairly reliable indicator of an economic downturn in the movie
industry as a whole during that period.

Which of the following, if ture,most helps to reconcile the discrepancy
noted above?

(a) the film stuios that produce today's mainstream movies occasionally
serve as distribution outlets for smaller budget independent films that
are also susceptible to pirating.
(b) Movie piraters exclusively target blockbuster hits,the existence of
which is inextricably tied to the financial success of the movie industry
during any given period
(c) Most  Movie piraters use small,handheld video cameras that are specially
designed to record images in the darkened environmment of a movie theater.
(d) The five largest film studios take in a disproportionate amount of movie
revenue compared to hundreds of smaller and independent film studios,
regardless of whether pirating activity during a specific period is high
or low
(e)  A movie pirater who is highly active in selling movies on the black market
  can sometimes make a full living doing so,while a less active Movie pirater
will usually have to supplement the income generated from pirated moviees.