The clumping of blood from mismatched blood types is a problem for a patient because

"The clumping of blood from mismatched blood types is a problem for a patient because it clogs the blood vessels. The correct option among all the options given in the question is the last option. The mismatch of blood types can lead to death of a person. Whenever the infused blood type is incompatible, the antibodies that are already present in the person will start attacking the new blood that was infused. Mainly the red blood cells get attacked and destroyed. This will result in the blood clotting and ultimately the clogging of the blood vessels. " by

That is true it is called an aftershock