Which sentence is not punctuated correctly?
a. i can see from your passport that you have been to madrid, spain; rome, italy; and athens, greece.
b. mr. giles, an avid collector of civil war memorabilia, was there; he didn't bring his slides.
c. several kinds of oranges sat on the table, however, tangerines are my favorite.
d. my grandparents have always wanted to travel; now, they are always visiting faraway places?