Which Time-Based Description of a Stage of Development in Pregnancy

Which time-based description of a stage of development in pregnancy is correct?

A) Viability-22 to 37 weeks of gestation since the last menstrual period (assuming a fetal weight greater than 500 g)
B) Term-pregnancy from the beginning of 38 weeks of gestation to the end of 42 weeks of gestation
C) Preterm-pregnancy from 20 to 28 weeks of gestation
D) Postdate-pregnancy that extends beyond 38 weeks of gestation