Choose the most appropriate option $($data collection technique$)$ that should be used for the following scenarios provided below:

After you changed the arrangement of items in your store, you want to observe if shoppers shop differently in the store.

You are conducting research regarding sexual assault. You are collecting data from the victims.

You are trying to find the effectiveness of three different advertising promotion techniques. You have designed three different advertisements $($for each promotion technique$)$ and would like to see which is the most effective through collecting and comparing data regarding 'purchase intention' and 'how good the respondents feel the deal is$\text{'}$ across the three promotion conditions. Also, you have a cost and time constraint for collecting the data.

you want to find out at which parts $($regions$)$ of the advertisement and for how long customers are looking at an advertisement you designed.