One quantity test basis for sorting untested young bulls is:

Correct option is A

The correct answer is (a) Genealogy

Explanation:

• Sorting or selecting young bulls for breeding programs involves evaluating their genetic potential before they have offspring.
• Genealogy, or pedigree records, is the primary quantitative basis for this selection.
• It involves analyzing the performance of the bull's ancestors, particularly its mother’s milk yield and father’s progeny record.
• This helps in estimating the 'Breeding Value' of the young bull.
• Once selected, these bulls undergo 'Progeny Testing' to confirm their genetic worth.

• Pedigree selection is cost-effective as it can be done at a very young age.
• Modern methods also include 'Genomic Selection' using DNA markers.

• These are qualitative physical traits and are not the primary basis for quantitative genetic sorting in breeding.

• Breed determines the general category, but sorting 'within' a group of young bulls of the same breed requires genealogical data.