An investigator is testing a new assessment of anxiety, and to examine the efficacy of this new measure he gives the assessment twice to a group of participants at the beginning of the fall and spring semesters. He is testing for reliability.
a) concurrent
b) inter-item
c) inter-rater
d) test-retest

Test-retest reliability

Explanation:

Test-retest reliability is a reliability that is used to assess the reliability and validity of a test. The test is implied on the same population at different time zone to find out whether the test is reliable or not. The main aim, of the test to assess the reliability. It means that consistently the test will be reliable and measure and the result would be consistently the same even after the test assesses again. This will lead to assess the reliability of the test.  

Thus here in the above context, the investigator was testing a new assessment of anxiety and to examine the efficacy of the test. He conducted the test twice on the same population at different time zone. This is conducted to assess test-retest reliability.

are there any options?