The first trimester completes by: (A) 12 completed weeks, (B) 13 completed weeks, (C) 14 completed weeks, (D) 16 completed weeks
Answer is C. Historically, the first trimester extends through completion of 14 weeks, the second through 28 weeks, and the third includes the 29th through 42nd weeks of pregnancy. Thus, there are three periods of 14 weeks each. (Ref: William's Obstetrics; 25th edition)