Rodney wears reading glasses, uses an ergonomically designed chair when he works at the computer, and exercises regularly to offset the effects of aging. He is also taking two courses at the local community college just for the sake of learning. What principle is at work here?

Selective optimization with compensation

Explanation: Based on the above scenario the principle at work is Selective optimization with compensation. This theory was developed by Paul and Margaret Baltes, that individuals try to maintain a balance in their lives by looking for the most effective way to compensate for physical and cognitive losses and to become better in activities they can already do well.

stewards ice box was the purchase of alaska from russia and it was called that because people thought it was not a good idea to purchase alaska