Dr Abaee Is Developing a New Intelligence Test

Multiple Choice

Dr. Abaee is developing a new intelligence test. He gives his test to a group of 100 participants and records their scores. Six months later, he retests the same participants on the test and finds that their scores match well with the scores they earned when tested six months earlier. What can we conclude about Dr. Abaee's test based on this study?

A) We can conclude nothing about his test.
B) His test is a good one.
C) His test is valid.
D) His test is reliable.