A 22-year-old client is 16 weeks pregnant.

(A) Naele’s rule is as follows: add 7 days to the 1st day of the last menstrual period, subtract 3 months, and then add 1 year. (B) Naele’s rule presumes that the woman has a 28-day menstrual cycle, with conception occurring on the 14th day of the cycle. Slight vaginal spotting may occur in early gestation for unknown reasons but is insignificant in the calculation of Naele’s rule. (C) Naele’s rule presumes that the woman has a 28-day menstrual cycle, with conception occurringon the 14th day of the cycle. Slight vaginal spotting may occur in early gestation for unknown reasons but is insignificant in the calculation of Naele’s rule. (D) Naele’s rule presumes that the woman has a 28-day menstrual cycle, with conception occurring on the 14thday of the cycle. Slight vaginal spotting may occur in early gestation for unknown reasons but is insignificant in the calculation of Naele’s rule.