An experiment was designed to test the effect of fatigue on muscle action. Students were broken into two groups: males and females. Both groups were given clothespins and instructed to count the number of times they could squeeze the clothespin in 30 seconds. The 10 girls were given 10 inch clothespins and the 15 boys were given 12 inch clothespins. After a 2 minute break, a second trial was done in which the girls squeezed their clothespin for 30 seconds and recorded their results and the boys squeezed their clothespins for 45 seconds and recorded the results.

Redesign this experiment to eliminate the errors identified in the design.

A) An experiment was designed to test the effect of fatigue on muscle action. Students were broken into two equal groups composed of both males and females. Both groups were given clothespins and instructed to count the number of times they could squeeze the clothespin in 30 seconds. Group 1 was given 10 inch clothespins and Group 2 was given 12 inch clothespins. After a 2 minute break, a second trial was done in which both groups squeezed their clothespins for 45 seconds and recorded the results.
B) An experiment was designed to test the effect of fatigue on muscle action. Students were broken into two groups: males and females. Both groups were given clothespins and instructed to count the number of times they could squeeze the clothespin in 30 seconds. Both groups were given 12 inch clothespins. After a 2 minute break, a second trial was done in which the girls squeezed their clothespin for 30 seconds and recorded their results and the boys squeezed their clothespins for 45 seconds and recorded the results.
C) An experiment was designed to test the effect of fatigue on muscle action. Students were broken into two groups: males and females. Both groups were given clothespins and instructed to count the number of times they could squeeze the clothespin in 30 seconds. Both groups of students were given 12 inch clothespins. Both groups were given a 2 minutes break. During the break, the girls rested and the boys did jumping jacks. Following the break, a second trial was done in which both groups squeezed their clothespin for 45 seconds and recorded their results.
Eliminate
D) An experiment was designed to test the effect of fatigue on muscle action. Students were broken into two groups composed of 25 students each. Both groups were composed of equal numbers of males and females from age 15-18. Students were given 10 inch clothespins and instructed to count the number of times they could squeeze the clothespin in 30 seconds and record their results. Group 1 was given a 1 minute rest break before proceeding to Trial 2. Group 2 was given no rest period. In Round 2, students squeezed the clothespin for 30 seconds and recorded their results in the data table provided.