What is the name of the coagulation factor that is deficient in patients with hemophilia C?

A Factor VIII
B Factor IX
C Factor XI
D Factor XII
Hemophilia C is a mild form of hemophilia caused by a deficiency of factor XI.
Robbins and Cotran Pathologic Basis of Disease
Hematology Hematology: Coagulation Disorders Hematology: Coagulation Disorders Medium MEDICAL Confidence: high