Which of the following trips, if any, will qualify for the travel expense deduction?

a.Paul, a romance language high school teacher, spends summer break in France, Portugal, and Spain improving his language skills.

b.Myrna went on a two-week vacation in Boston. While there, she visited her employer's home office to have lunch with former coworkers.

c.Dr. Brown, a self-employed surgeon, attends a two-day seminar on financial planning.

d.Dr. Jones, a self-employed general dentist, attends a two-day seminar on developing a dental practice.

e.All of these choices are correct.