Answer:
a. combine the samples and check for coagulation
Step-by-step explanation:
a. combine the samples and check for coagulation
We know that hemophilia is X linked recessive disorder which arises basically due to lacking of clotting factor in the blood (Factor VIII or Factor IX). According to the condition provided if pathology is closed so doctor can not perform the specific test so only their is chance to combine the sample of patient blood with the classic hemophiliac blood sample.As here doctor is sure that the blood sample available in his hospital is of hemophiliac patients so it does not contain clotting factor. When he mix both blood and then if the blood show coagulation it means David do not have hemophilia but if after mixing both the blood sample coagulation will not occur so David may be hemophilic.