C, apply your work meaningfully and to your intended audience when creating it.
Beginning, worst
(personally I like having the order 13542, 1 being best, 5 being worst, so your impression is good and you leave off with a good impression as well instead of a sour/underwhelming work
Leave a portfolio for the interviewer to review
B if it’s a general portfolio
I believe the answer is "Acoustics"
Hope this helps!
