Biology
Medium
Question
“lub” sound is produced after _________ ?
A
The ventricles are fully contracted
B
The ventricles start to relax
C
The bicuspid and tricuspid valves suddenly close
✓ Official correct answer
D
The semilunar valves are closed
Community credibility
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A
The ventricles are fully contracted
No member explanations yet for this option.
B
The ventricles start to relax
No member explanations yet for this option.
C
The bicuspid and tricuspid valves suddenly close
No member explanations yet for this option.
D
The semilunar valves are closed
No member explanations yet for this option.