A variety of opossum that lives on an island with no predators lives much longer than its relatives on the mainland, even when both are kept safely in a zoo. The island variant's genes have been selected for slow aging, whereas the mainland variant's genes have been selected for quick reproduction. The island opossum exhibits __________ selection, and the mainland opossum exhibits __________ selection.

• A. r; K
• B. nutrient; territory
• C. iteroparity; semelparity
• D. clumped; uniform
• E. K; r