Which of the following is a functional plasma enzyme:

Functional plasma enzymes are those enzymes which are present in plasma as they have function in plasma. E.g.: Lipoprotein lipase Clotting Factors e.g. Prothrombin Non -functional plasma enzymes do not have function in plasma, they are present inside cells and tissues. E.g.: SGOT is present in liver and hea. For option A , LDH , only one type of LDH i.e. type 2 is functional plasma enzyme. So,Prothrombin>>>LDH because out of 5 isotypes of LDH only type 2 is a functional plasma enzyme. So, prothrombin is a better option to be marked.