Which of the following is a common type of anticoagulant?

A common type of anticoagulant inhibits the formation of blood clots and is critical in various medical and laboratory settings. In this context, boric acid, while primarily known for its antiseptic and insecticidal properties, can have anticoagulant effects by acting as a buffering agent in some biological systems. Its incorporation addresses the need for maintaining pH and preventing clot formation in certain applications.

In contrast, phenol is primarily an antiseptic and has not established significant uses as an anticoagulant. Acetic acid is notable mainly for its use in biological buffers and as a preservative but does not function as an anticoagulant. Tris buffer is utilized to maintain a stable pH in biological and biochemical applications, but it is not designed to have anticoagulant properties. Thus, the identification of boric acid as a common type of anticoagulant acknowledges its role in specific contexts where blood sample integrity is maintained.