Silas took the College Aptitude Test (CAT) when he was a junior in high school, and he attained a very high score on the test. When Silas was in college, he was suspended his first year, and when he was readmitted, he ended up dropping out because he was doing poorly in all his classes. When Silas went for career counseling, he retook the CAT, and again he earned a very high score. Based on Silas' experience, you might conclude that the CAT has .

high reliability, but low validity                  

Explanation:

Reliability: In psychological research, the term "reliability" is described as the consistency of a specific measuring test or research study i.e, it should give rise to the similar outcome if done after a time period.

Validity: In psychological research, the term "validity" is described as the degree to which a specific test or research measures what is claimed to measure or analyze.

In the question above, the given statement signifies high reliability but low validity.                                                              

i would say b. research typically uses a variety of sources