Question

lo 2.2. what are the four blood types in the abo system?
b, a, ab, o+
a, b, o, ab-
ab, o, a, b+
o, a, ab, b-
a, b, ab, o

Explanation:

The ABO blood group system classifies blood types based on the presence or absence of A and B antigens on red blood cells. The four main types are A (has A antigens), B (has B antigens), AB (has both A and B antigens), and O (has neither A nor B antigens). The '+' or '-' (related to Rh factor) is not part of the ABO system's basic four - type classification.

Answer:

A, B, AB, O