Which of the following reactions is correct?

Among the following compounds,which one is not responsible for the depletion of the ozone layer?

Carbon cannot be used in the reduction of $Al_2O_3$ because :

$A$ horizontal pipe of non-uniform cross-section allows water to flow through it with a velocity $1 \ m/s$ when pressure is $50 \ kPa$ at a point. If the velocity of flow has to be $2 \ m/s$ at some other point,the pressure at that point should be (in $kPa$)

Which layer of the uterus undergoes cyclical changes during the menstrual cycle?

What is the probability of a couple having four sons?