To determine if a new medication to lower blood pressure in adults would have the unpleasant side effect of weight gain, the medication was given to 40 adults with high blood pressure, their weight was measured before and after a month on this medication. It was determined that weight measurments for this group of people are NOT normally distributed. Which is the appropriate test to use to perform a hypothesis test to determine if the medication causes weight gain?
A) Paired t-test
B) Sign test
C) Mann-Whitney U test
D) Two-Sample t-test