Gavin's Study Compared Reading Error Rates and Reading Comprehension Scores

Multiple Choice

Gavin's study compared reading error rates and reading comprehension scores between two groups of 50 third-grade students that received different reading programs. His t-test data analysis did not indicate any differences between the two types of instruction.
-The treatment variable in Gavin's study is

A) error rates.
B) third graders.
C) reading instruction.
D) reading comprehension.