Answer:
d. N₂
Explanation:
Bends -
As the scuba divers go deep inside the sea the pressure deep inside the sea is very high , and during this high pressure , number of gases ( specially nitrogen gas ) get dissolved in the blood vessels .
And ,as soon as the divers comes back to the surface , the pressure gets back to normal , i.e. , reduces , and hence , the dissolved gases tries to escape out by causing bubbles of nitrogen gas , which is very painful and can lead to low back pain , numb legs , weakness in body , vomiting , dizziness and can be fatal .
Hence, to avoid the condition of bends , the gas cylinder of divers are flushed with diluted air containing 11.7% helium, 56.2% nitrogen and 32.1% oxygen .
