Which of the following is $NOT$ a character of open circulation?

Given below are four statements $(i-iv)$ regarding the human blood circulatory system.
$(i)$ Arteries are thick-walled and have a narrow lumen as compared to veins.
$(ii)$ Angina is acute chest pain when the blood circulation to the heart muscle is reduced.
$(iii)$ Persons with blood group $AB$ can donate blood to any person with any blood group under the $ABO$ system.
$(iv)$ Calcium ions play a very important role in blood clotting.
Which two of the above statements are correct?

Assertion $A$: In an open circulatory system,the blood volume is high,but the blood pressure is low and irregular.
Reason $R$: In a closed circulatory system,the blood volume is limited,and the blood pressure is high and regular.
Which option is correct for Assertion $A$ and Reason $R$?

Intracellular fluid and extracellular fluid constitute what percentage of total body weight,respectively?

In normal humans,the time taken for normal blood clotting is:

Differentiate between closed circulatory system and open circulatory system.