Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.
Q: Problem: first column specifies the no of days prior to departure information. second column specifies the percentage discount offered. 0 - 6 days = = > 0 % 7 - 13 days = = > 10 % 14 - 29 days = = > 25 % 30 days or more = = > 40 % the table above shows the discount structure for advanced purchase of tickets at a particular airline. a passenger bought a ticket at this airline for $ 1050. the ticket agent informed her that, had she purchased the ticket one day later, she would have paid $ 210 more. how many days before her departure did she purchase her ticket.
Options: a. 6, b. 7, c. 13, d. 14, e. 29
A: 
d