1. A. This is a posttest only design. 1. B. The major threat to internal validity in this case is instrumentation. We can see that there has been a change in the way measurement of the behaviour has taken place in terms of decreasing amount of distance between the observer and the participant. 2. A. This is a repeated measures design. 2. B. The main threat to internal validity in this case is history. Because the experiment have taken place over an extended period of time, there are chances that the participants were exposed to certain events or situations in between which may have impacted the independent and dependent variable relationship.

please draw the graph not answer the questions only, we need the graphs ..