trip vs tour

[micaelo]

Hi, I seem to be having some problems with the following multiple-choice cloze:
Tony Wheeler and his wife Maureen started the company known as Lonely Planet afer a year-long journey across Asia in 1973. They were amazed to find that their friends were eager to read their accounts of the ..............., which had taken them well off the beaten track.
a. travel b. voyage d. trip d.tour
The answer key gives "trip" as the only correct answer, and it comes up again later in the paragraph, but I really can't see why "tour" is not correct too, as they visit several places. Thanks.

[BobK]

I agree - I prefer 'tour'.

b