According to Naegele's rule, calculate EDD of a patient with LMP 9/1/2017:

ANS. A* Adding 7 days + 9 months to LMP gives EDD* Naegele's rule is based on 28 days regular cycle* If the cycle is shorter or longer than 28 days, EDD will be corrected and written as corrected EDD.For irregular cycles:1. If she is having 40 days cycle regularly, to get corrected EDD, add (40-28) with the EDD calculated from LMP.2. If she is having 21 days cycle regularly, to get corrected EDD, substract (28-21) 7 with the EDD calculated from LMP.