Which is the correct option to complete the paragraph below?

Which is the correct option to complete the paragraph below?

The power of a thank-you note

Thank-you notes might seem old-fashioned ________ there's plenty of value to be found in the tradition. ________ a study by Accountemps, just 24% of job applicants send thank-you notes after interviews - ________ 80% of hiring managers who receive them say they are useful in evaluating the potential of applicants. Proponents of thank-you notes say they are an inexpensive way to strengthen a relationship ________ show the applicant cares about the job.

(Adapted from https://www.linkedin.com)