Final answer:
In a normal or reactive Non-Stress Test (NST), the fetal heart rate should increase by at least 15 bpm over 15 seconds after fetal movement, making the correct answer C) 15 bpm.
Step-by-step explanation:
The student asked what a normal or reactive Non-Stress Test (NST) means regarding fetal heart rate (FHR) increases after fetal movement. To be considered normal or reactive, the FHR should increase by at least 15 bpm over 15 seconds following fetal movement. Therefore, the correct answer in this case is C) 15 bpm. This type of monitoring is important in obstetrics to assess the well-being of the fetus, as part of the overall fetal health evaluation which includes assessments like the Apgar score immediately after birth.