Statement — Any further increase in city pollution from industrial effluent and automobile exhaust will pose a severe threat to inhabitants.\nCourses of Action:\nI. Close all factories in the city immediately.\nII. Allow automobiles to ply only four hours a day.\nIII. The Government should restrict issuing fresh licenses to factories and automobiles.

Introduction / Context:
When further increases will be critical, proportionate, lawful controls are appropriate. Extreme blanket closures or four-hour caps are impractical and economically damaging.

Given Data / Assumptions:

• I: Shut all factories.
• II: Limit all vehicles to four hours/day.
• III: Restrict fresh licenses (growth control), alongside standards.

Concept / Approach:
III curbs additional load while authorities tighten compliance (emission standards, inspection, fuel quality) on existing sources. I and II are disproportionate and likely unlawful absent emergency powers.

Final Answer:
Only III follows.