Answer:
A. You need to draw a straight line that increases from left to right. Try and get the same amount of plots on the top and bottom of the line and go through one or two of the plots. Don't connect the dots, though.
B. This scatter plot demonstrates a positive association between a person's height and weight because the trendline increases from left to right. According to this data, as weight increases, so does height. The more someone weighs, the more likely they are to be tall.