A Friend of Yours Was Asked to Evaluate the Effect

A friend of yours was asked to evaluate the effect of an advertisement campaign designed to get people to have their blood pressure checked.After examining the records kept by the blood pressure units in the target area,your friend showed you the following graph where X indicates an observation.

What will you tell your friend?

A) The ad campaign is producing the intended effect.
B) The independent variable, the campaign, is having an effect on the dependent variable, the percent having their blood pressure checked.
C) More observations are needed to determine whether the independent variable is having the intended effect.
D) The ad campaign has no effect.
E) There is no relation between the two variables.