Ashwin wants to promote his product i.e., a bicycle and wants to reach a large number of people over a vast geographical area. Suggest a promotional method, he should adopt:

The correct option is Advertising.

To understand why this is the most suitable promotional method for Ashwin's business goals, let us analyze the requirements and match them with the characteristics of the promotional tools:

1. Ashwin's Goals:
- Reach a large number of people: He needs a medium that has a massive audience size.
- Cover a vast geographical area: The target audience is spread out across different regions, cities, or even countries.
- Product type: A bicycle is a consumer product that has a broad, diverse market of users (children, students, fitness enthusiasts, commuters).

2. Evaluating the Options:
- Personal Selling: Involves face-to-face interaction between the seller and prospective customers. While highly persuasive, it is extremely limited in reach, highly time-consuming, expensive per contact, and impractical for covering a vast geographical area quickly.
- Sales Promotion: Refers to short-term incentives (like discounts, coupons, or contests) to stimulate immediate sales. While effective, it is usually used in combination with other methods to boost sales rather than serving as the primary tool to build wide geographical awareness from scratch.
- Public Promotion (Public Relations): Focuses on building a positive image and managing relations with the public. While it helps build credibility, it is less direct and harder to control in terms of targeted product promotion across a specific, massive geographic region.
- Advertising: This is a paid, non-personal form of communication used to present and promote ideas, goods, or services by an identified sponsor. It uses mass media such as television, radio, newspapers, social media, and billboards.

3. Why Advertising is the Correct Choice:
- Mass Reach: Advertising can transmit the message to thousands or millions of potential customers simultaneously.
- Geographical Spread: Through digital ads, television, or print media, Ashwin can easily market his bicycle to people living across different states or countries without needing physical representatives everywhere.
- Cost-efficiency: Although the total cost of advertising can be high, the cost per contact (cost per person reached) is extremely low compared to personal selling.

Therefore, to promote his bicycle to a massive audience over a broad geographic area, Ashwin should adopt Advertising.