From the test results, the victim is O+. The clumping indicates the presence of a rhesus factor.
There are four human blood groups which are;
A
B
AB
O
A person can have any of these blood groups. Those who have blood group O lack antigens A and B in blood hence they do not agglutinate in a blood test with antibodies A and B.
Also, the fact that there is clumping in the rhesus test indicates that the blood is rhesus positive.
