An older client comes to the emergency department experiencing chest pain and shortness of breath. An arterial blood gas is ordered. Which of the following ABG results indicates respiratory acidosis?...

An older client comes to the emergency department experiencing chest pain and shortness of breath. An arterial blood gas is ordered. Which of the following ABG results indicates respiratory acidosis?

1. PH 7.54; PaCO2 28 mmHg; HCO3 22 mEq/L

 2. PH 7.32; PaCO2 46 mmHg; HCO3 24 mEq/L

 3. PH 7.31; PaCO2 35 mmHg; HCO3 20 mEq/L

4. PH.50; PaCO2 37 mmHg; HCO3 28 mEq/L