Which of the Following Researchers Is Using an Acceptable Operational

Multiple Choice

Which of the following researchers is using an acceptable operational definition of a variable?

A) Dr. Pham defines intelligence as one's ability to problem solve.
B) Dr. Selkirk defines aggression as the number of swear words spoken in an hour.
C) Dr. Mellek defines social anxiety as the intensity of embarrassment in social situations.
D) Dr. Nelson defines memory as the earliest childhood memory available.