Which of the following is true about scientific theories?

A) All theories are equally plausible.
B) The quality of a theory cannot be measured by the number of people who believe it to be true.
C) Theories are the same thing as opinions or beliefs.
D) A theory is only valid if it has been proven to be true.

Answer: B
Rationale: There are many misconceptions about theories. The textbook specifically addresses three common issues: theories are not the same thing as opinions or beliefs, all theories are not equally plausible, and a measure of a good theory is not the number of people who believe it to be true.