What factors are specifically monitored by the PT test?

The prothrombin time (PT) test is primarily used to evaluate the extrinsic pathway of coagulation, as well as to monitor the effectiveness of anticoagulation therapy, particularly with warfarin. In this context, the correct answer includes the factors involved in the extrinsic pathway.

Factor I (Fibrinogen) is part of the common pathway and is essential for the final stages of clot formation. Factor II (Prothrombin) is the precursor to thrombin, which is crucial for clotting. Factor V acts as a cofactor in several reactions that lead up to clot formation. Factor VII is key to starting the extrinsic pathway of coagulation when tissue factor is present. Factor X is the point of convergence where both extrinsic and intrinsic pathways lead to the common coagulation pathway.

Given that the PT test assesses the integrity of this extrinsic pathway and the common pathway, the inclusion of Factors I, II, V, VII, and X is directly relevant. This makes the selected answer accurate, as all these factors play important roles in the coagulation process evaluated by the PT test.