Step 1: Identify the root problem: a sharp rise in accidents at one junction, which can stem from both physical road conditions and driver behaviour.
Step 2: Test course I - installing signals and speed breakers is a structural, engineering fix that addresses the physical cause of accidents, so it follows.
Step 3: Test course II - deploying traffic police addresses the behavioural cause, since regulation and enforcement directly influence how drivers act at the junction, so it also follows.
Step 4: Since the two courses address different but equally valid facets of the same underlying safety problem, both are reasonable and complementary.
Correct option: (4) Both courses of action follow.