A researcher studied the influence of crowding (low, medium, and high) on reading comprehension between two types of third graders. The children were randomly assigned to each crowding condition, but within each of those groups they were divided into two separate groups based on an independent test of verbal fluency. In the study, each child read one 750-word passage (with either low, medium, or high crowding) and was subsequently tested on their reading comprehension. Which of the following describes an interaction in the context of Dr. Read's study? a. The children with high verbal IQ in the low crowding condition had the highest reading comprehension scores.
b. Reading comprehension was better in the low crowding condition than in the high crowding condition.
c. Crowding reduced reading comprehension, but only for the children who had low verbal IQ.
d. Reading comprehension was better in the high verbal IQ group compared to the low verbal IQ group.