Select the outbreak investigation step that corresponds to each example presented below.

Eight hotel guests developed pneumonia after staying at a hotel in Ocean City, MD$.$ Legionella pneumophila serogroup $1$ was recovered from multiple sites in the hotel, including showers and faucets in guest rooms.

A food consumption questionnaire administered to $50$ students with hepatitis A and $50$ well students revealed that ill students were much more likely than well students $--$Select$-$Analytic epidemiologic investigation to have drunk milk and eaten donuts recently.

Marijuana samples provided by teenage and young adult cases in a Michigan gastrointestinal illness outbreak were positive for Salmonella muenchen; and all isolates contained two unusual low molecular$-$weight plasmids.