Answer:
Observational study.
Step-by-step explanation:
In Statistics, sampling can be defined as a process used to collect or select data (objects, observations, or individuals) from a larger statistical population using specific procedures.
There are various types of sampling used by researchers and these are;
1. Random sampling.
2. Systematic sampling.
3. Stratified sampling.
4. Cluster sampling.
5. Opportunity or convenience sampling.
An observational study can be defined as a type of study in which a researcher observes and measures the effect of a diagnostic test, risk factors, or treatments on individuals without intervening, changing or manipulating who are or aren't exposed to it (controlled conditions).
In this scenario, Alicia is conducting an observational study because the study was required to be conducted without interacting with the customers so as to avoid influencing their behavior and choices.