Select the correct option:
$(1)$ The respiratory rhythm center for breathing regulation is located in the medulla oblongata of the brain.
$(2)$ Each hemoglobin molecule can carry a maximum of $4$ molecules of $O_2$. (Note: The original question mentioned $CO_2$,which is incorrect; hemoglobin primarily transports $O_2$.)

• A
  $(1)$ True,$(2)$ $4$ molecules
• B
  $(1)$ True,$(2)$ $10$ molecules
• C
  $(1)$ False,$(2)$ $4$ molecules
• D
  $(1)$ False,$(2)$ $10$ molecules