Final answer:
The primary audience of the letter will depend on the context, and the writing should be shaped to connect effectively with the selected audience.
Step-by-step explanation:
The primary audience of the letter will depend on the specific context, but possible audiences could include the student's instructor, classmates, other students or administrators on their campus, or people in their community. To shape the writing to connect effectively with the primary audience, the student should consider the tone, language, and level of formality that would be appropriate for that audience. Secondary audiences, such as people outside of class, should also be considered, and their needs and expectations should be taken into account as well.