Two tests were given to student in the sixth grade. Test A contained 25 items and was given to a group of low - achieving sixth graders. Test B contained 50 items and was given to the other sixth-grade students in the school who were of mixed ability. Which test would more likely have a higher reliability coefficient and why?

Test A because the test was shorter and was administered to a homogeneous group of students

Test A because it was given before Test B and might have influenced the scores on Test B

Test B because the test was longer and was administered to a heterogeneous group of students

Test B, because the test was taken by a group of student who would perform better on the test