How should the researchers decide which pizza be tasted first?

Random selection:

- Flip a coin to determine which pizza should be tasted first.

Systematic selection:

- Flip a coin to determine the order in which the pizzas will be tasted, then stick to that order.

Convenience selection:

- Taste the pizza that is closest or easiest to access first.

Stratified selection:

- Assign each pizza a number and draw a number to select which pizza will be tasted first.