T Sold Textbooks for a Living by Visiting Different Teaching

T sold textbooks for a living by visiting different teaching institutions and showing samples of various books to professors.She typically carried about 100 books in her Volkswagen on her way from home to various local universities that she regularly called upon.Last year a sudden increase in the number of textbooks revised caused T to increase her quantity of samples from 100 to 300 books.To carry all of the books, T rented a trailer that she pulled behind her Volkswagen.T sought to deduct the cost of the trailer on her tax return.T will

A) Be allowed to deduct the cost of the trailer as an additional cost attributable to carrying the items that T needs for the cost of doing business normally
B) Not be allowed to deduct the cost of the trailer.However, T could have deducted the additional cost of hauling the new books if she had bought a larger car and used the "same mode" of transporting them as before
C) Not be allowed to deduct the cost of the trailer because T is still essentially using the "same mode" of hauling books as before, i.e., with a car
D) Be allowed to deduct the cost of renting the trailer because she is not using the "same mode" of hauling the new books that she used for the old ones