What is the primary difference between aptitude and achievement tests?
A) Aptitude tests are designed to predict performance in general; achievement tests measure what you've already learned.
B) Aptitude tests have high reliability and validity; achievement tests have poor reliability and validity.
C) Aptitude tests usually contain open-ended questions (fill-in-the-blank), while achievement tests are more objective.
D) Aptitude tests are less expensive to administer than achievement tests
