In an effort to figure out why application rates are slipping, your college decides to set up an experiment to determine why students who are interested in the college decide to enroll or not

In an effort to figure out why application rates are slipping, your college decides to set up an experiment to determine why students who are interested in the college decide to enroll or not. The college decides to send out a questionnaire to everyone who submitted an application to the college in 2017. In this experiment, a survey was used to collect data. What potential bias does this method raise?

A. Observational bias.

B. Self-selection bias.

C. Transformational bias.

D. Subjective bias.