In the experiment illustrated, $100\,\text{cm}^3$ of clean, dry air is sent to and fro through a tube packed with heated copper until the air volume no longer falls. The entire gas sample is then forced into a single syringe. What reading is obtained on this gas syringe?
- A$0\,\text{cm}^3$
- B$21\,\text{cm}^3$
- C$79\,\text{cm}^3$
- D$100\,\text{cm}^3$