Answer to Question 1
B
Sinus bradycardia, which is a heart rate of 60 bpm or less, can be caused by conditions such as myocardial ischemia, electrolyte imbalances, or heart block.
Answer to Question 2
D
Naegele's rule is take the date of the first day of the last menstrual period, subtract 3 months, and add 7 days.