What type of reliability estimate would be most appropriate for the following measuring instruments? a

What type of reliability estimate would be most appropriate for the following measuring instruments?

a. A multiple-choice achievement test will be used as the dependent variable in an experimental study.

b. A researcher will study changes in attitude and will administer one form of an attitude scale as both the premeasure and the postmeasure.

c. A researcher has two forms of an achievement test; she administered one form at the beginning of the study and the other at the conclusion of the study. She wants to determine the reliability of the test.