A Group of Teachers Develops a Math Curriculum to Help

A group of teachers develops a math curriculum to help students increase their scores on required tests in math.The teachers find promising results with the students in their school,so they develop a plan to test the curriculum in all of the schools in their county.This plan shows that the teachers recognize the importance of

A) proving that their theory is falsifiable.
B) demonstrating their pathological skepticism.
C) showing that required math tests are invalid.
D) replicating the original findings to increase confidence in them.