Research Studies on Viagra Users Indicate That

Research studies on Viagra users indicate that

A) most users are able to engage in intercourse and are very satisfied with the results.
B) approximately half of the users are able to engage in intercourse and are highly satisfied with results.
C) 61% of men were able to get erections adequate for intercourse, but only 32% rated the results as 'good'.
D) most users were unable to engage in intercourse and were not satisfied with results.