Concept:Discontinuous variation describes traits that fall into distinct separate categories with no intermediate forms.
Explanation:Height, weight, and colour often show continuous variation because they can range across many intermediate values.
Sex, blood group, and fingerprint patterns are discrete traits.
Fingerprint patterns are grouped into clear types such as loops, whorls, and arches, with no in-between patterns.
Blood groups are also distinct types: A, B, AB, or O, and an individual cannot have an intermediate blood group.
Therefore, the pair that best represents discontinuous variation is fingerprint and blood group.
Answer:D. fingerprint and blood group