• Ergonomic Workload Categorization by Oxygen Uptake:
• Human physical workload classification based on steady-state oxygen consumption rate ($\dot{V}_{\text{O}_2}$ in L/min):
• Light work: $\lt 0.5\text{ L/min}$ (Energy expenditure $\lt 10.5\text{ kJ/min}$, Heart rate $\lt 90\text{ bpm}$)
• Moderate work: $0.5 - 1.0\text{ L/min}$ (Energy expenditure $10.5 - 21.0\text{ kJ/min}$, Heart rate $90 - 110\text{ bpm}$)
• Heavy work: $1.0 - 1.5\text{ L/min}$ (Energy expenditure $21.0 - 31.5\text{ kJ/min}$, Heart rate $110 - 130\text{ bpm}$)
• Very heavy work: $1.5 - 2.0\text{ L/min}$ (Energy expenditure $31.5 - 42.0\text{ kJ/min}$, Heart rate $130 - 150\text{ bpm}$)
• Extremely heavy work: $\gt 2.0\text{ L/min}$ (Energy expenditure $\gt 42.0\text{ kJ/min}$, Heart rate $\gt 150\text{ bpm}$)
• Evaluation: An oxygen consumption rate of $2.5\text{ L/min}$ falls distinctly into the extremely heavy work category.
• Conclusion: Extremely heavy work (Option 2).

Correct option: (2) Extremely heavy work