True about significant variable decelerations is:

Ans. is d, i.e. Drop in fetal heart rate to less than 70 bpm for 60 seconds Classification of variable decelerationDecelerationDefinitionMild variable deceleration>80 bpm irrespective of duration, or <30 seconds irrespective of depth or between FHR-70 to 80 bpm lasting for 60 secondsModerate variable deceleration>70 bpm lasting for 30 to 60 seconds or between FHR-70 to 80 bpm lasting for > 60 secondsSevere variable deceleration< 70 bpm lasting for 60 seconds