Which of the following is $NOT$ a characteristic property of hemoglobin?

Which of the following modified proteins is responsible for spontaneous blood clotting?

Which of the following vitamins is essential for the maturation of erythrocytes?

Given below are two statements:
Statement $I$:
The coagulum is formed of a network of threads called thrombins.
Statement $II$:
Spleen is the graveyard of erythrocytes.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which of the following components, if introduced into the bloodstream, will cause blood clotting at the site of introduction?

Which blood group can be given to patients of any blood group?