The reason option (1) is the appropriate choice for addressing the letter when applying for the post of a Sales Executive is as follows:

- "The Personnel Manager" is the appropriate recipient for a job application. They are responsible for handling recruitment and hiring processes within a company.

- "ABC Company" is the specific company to which Ravi is applying for the Sales Executive position.

- "Worli" is the location of the company's office, providing a complete address.

This option ensures that the letter reaches the relevant person in the company responsible for hiring decisions, making it the most suitable choice for a job application.