Full question attached
Answer:
Option C: because the percent of children compared differ too much
Explanation:
Sample Proportion of students from Montessori = students that participated from Montessori /total number of students assigned to Montessori
=30/54= 0.56
Sample proportion of students from other schools = students that participated I'm the study /total number of students assigned to other schools
=25/112
=0.22
We observe that there is a large difference(0.56-0.22) between the two sample proportions hence the bias