Allowing for the Cutback Adjustment (50% Reduction for Meals and Entertainment)

Allowing for the cutback adjustment (50% reduction for meals and entertainment) , which of the following trips, if any, will qualify for the travel expense deduction?

A) Dr. Jones, a general dentist, attends a two-day seminar on developing a dental practice.
B) Dr. Brown, a 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 two­week vacation in Boston. While there, she visited her employer's home office to have lunch with former co-workers.
E) All of the above.