A general estimate is that of all conceptions end in a miscarriage. 5-10% 10-20% 20-30% 30-40%

 30-40%

Explanation:

The estimated figure is that spontaneous abortion occurs in approximately 1 in 4 recognized pregnancies, with 85% of those occurring in the first trimester (weeks 1 to 12). A 'late' miscarriage, which is much less common, can occur between weeks 13 and 24 of pregnancy.

Where a miscarriage usually occurs in the first 3 months of pregnancy, before 12 weeks of gestation. A small fraction of pregnancy losses, which occurs in less than 1% of pregnancies, are called fetal deaths, since they occur after 20 weeks of gestation.

b is the best answer for this question.

it also supports my hypothesis. if you rest first you can squeeze the clothespin more times. from the data i collected the average of the eight people concluded exercise makes your muscles more fatigued and less able to squeeze the clothespin compared to resting before squeezing.