• Respiratory Blood Gas Values:
• Systemic Arterial Blood:
• Partial pressure of oxygen ($pO_2$): $\approx 95 - 100\text{ mmHg}$ (oxygen saturation $\approx 98\%$).
• Partial pressure of carbon dioxide ($pCO_2$): $\approx 40\text{ mmHg}$.
• Mixed Venous Blood (Pulmonary Artery / Right Ventricle):
• After delivering oxygen to metabolizing peripheral tissues:
• $pO_2 \approx 40\text{ mmHg}$ (oxygen saturation $\approx 75\%$).
• $pCO_2 \approx 45 - 46\text{ mmHg}$.
• nalysis:
• (40 mmHg): Correct physiological value for venous blood.

Correct option: (1) 40 mmHg