Which of the Following Trips, If Any, Will Qualify for the Travel

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

A) Dr.Jones, a self-employed general dentist, attends a two-day seminar on developing a dental practice.
B) Dr.Brown, a self-employed surgeon, attends a two-day seminar on financial planning.
C) Paul, a romance language high school teacher, spends summer break in France, Portugal, and Spain improving his language skills.
D) Myrna went on a two-week vacation in Boston.While there, she visited her employer's home office to have lunch with former coworkers.
E) All of these.