While planning a lesson, one of the objectives is to enable learners to produce typical business communication with customers. This objective matches with one of the types of text genres listed below :

The correct answer is Letter.

Business communication with customers traditionally and primary involves writing formal letters (such as inquiry letters, complaint letters, sales letters, and offer letters) or their modern electronic equivalents (emails formatted as formal letters). Therefore, the genre that directly matches the objective of producing typical business communication with customers is a Letter.

Let us examine why the other options are less appropriate:

1. Report: Usually an internal document or formal presentation of research, analysis, and data, rather than direct day-to-day business communication with customers.
2. Description: A rhetorical style or text format used to describe features or processes, but not a full business communication text genre by itself.
3. Article: A genre written for publication in magazines, newspapers, or journals to inform a wide public audience, not tailored business communication for individual customers.
4. Letter: The standard genre specifically designed for direct, professional, and structured communication between a business and its customers.