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.

[EX Q]: Problem: a ( 3, w ^ 3 ) is the ( x, y ) coordinate of point located on the parabola y = x ^ 2 - 1. what is the value of w ?
Options: a. 2., b. 4., c. 5., d. 6., e. 9.
[EX A]: a

[EX Q]: Problem: if the price of a certain computer increased 30 percent from b dollars to 351 dollars, then 2 b =
Options: a. 540, b. 570, c. 619, d. 649, e. 700
[EX A]: a

[EX Q]: Problem: sally has a gold credit card with a certain spending limit, and a platinum card with twice the spending limit of the gold card. currently, she has a balance on her gold card that is 1 / 3 of the spending limit on that card, and she has a balance on her platinum card that is 1 / 7 of the spending limit on that card. if sally transfers the entire balance on her gold card to her platinum card, what portion of her limit on the platinum card will remain unspent ?
Options: a. 11 / 30, b. 29 / 42, c. 17 / 30, d. 19 / 30, e. 11 / 15
[EX A]:
b