Step 1: Understanding the Concept:
Animal breeding relies on relationships.
Some relatives are closer than others.
Step 2: Key Formula or Approach:
No specific formula.
Need to understand relationships in breeding.
Step 3: Detailed Explanation:
Full-sibs and half-sibs are the closest relatives.
They share a high proportion of genes.
Pedigree is a record of ancestry.
Progenies are offspring.
Sire and dam are parents.
The closest relatives for breeding purposes are full-sibs and half-sibs.
Step 4: Final Answer:
The closest relatives are full-sibs and half-sibs.
Hence, the correct option is (B).