How can you apply the concept of ethics to the subject of animal testing?

1. efficient use of space

2. elimination of groundwater contamination

3. energy generation

4. lower carbon footprint

that is wrong, its not thymus.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]