Step 1: Understanding the Concept:
The question asks for the reasoning behind the profitability of a cigarette shop on a busy road.
Step 2: Detailed Explanation:
The passage says: "It was bound to be profitable, he felt." The implied reasoning is that a busy road naturally attracts a large number of customers, ensuring business viability.
Step 3: Final Answer:
Hence, the correct option is (D) a cigarette shop on a busy road would attract a large number of customers.