Reference: A neighborhood in Florida plans to buy all the full-time residents bicycles to get around the neighborhood in an attempt to reduce their carbon footprint. The neighborhood gives all the residents their bicycles in March 2021. The neighborhood uses the following metrics to determine if the program was successful:

• Number of cars per hour at the primary intersection
• Number of bicycles parked at the main beach

The neighborhood makes two comparisons, they compare these metrics over a two month period (April and May) after the bikes were given to residents (in year 2021). A comparison group was set up for April and May of 2020. The neighborhood has a total of 1000 full-time residents that were living in the neighborhood that received a bike in 2021.

Question: What about this design allows for stronger conclusions than some other observational designs?

Options: The large number of residents receiving the bicycles

The neighborhood randomly selected residents to receive the bicycles.

The two groups, having a bicycle vs not being given the bicycle, would be similar on average