Final answer:
Using passive voice in a cover letter can confuse readers and weaken the writing. Active voice is preferred for its clarity and directness, making a better impression on prospective employers.
Step-by-step explanation:
If you were to use passive voice in a professional cover letter, the effect this would most likely have on your reader is that your reader may be confused by your syntax (a). While passive voice can be used effectively for certain purposes, such as in scientific writing where objectivity is favored, in a cover letter, clarity and directness are preferred. Active voice tends to make sentences stronger, clearer, and more concise, which contributes to a more convincing and compelling writing style.
Using active voice in a cover letter also demonstrates a proactive and decisive personality, which is typically more appealing to prospective employers. In contrast, passive voice may detract from the vitality of the writing and can make the document appear wordy. Since a cover letter is an opportunity to showcase your communication skills and professionalism, it's important to make the best impression on your reader by adhering to clear and effective writing practices, which include minimizing the use of passive voice.