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.

Example Input: Problem: if the sum of 5 consecutive even positive integers is a, then the sum of the next 5 even consecutive integers in terms of a is :
Options: a. a + 5, b. a + 10, c. a + 25, d. a + 50, e. 2 a + 5
Example Output: d

Example Input: Problem: a train running at the speed of 20 km / hr crosses a post in 10 seconds. what is the length of the train ?
Options: a. 150, b. 250, c. 415, d. 200, e. 312
Example Output: d

Example Input: Problem: a farmer has an apple orchard consisting of fuji and gala apple trees. due to high winds this year 10 % of his trees cross pollinated. the number of his trees that are pure fuji plus the cross - pollinated ones totals 153, while 3 / 4 of all his trees are pure fuji. how many of his trees are pure gala ?
Options: a. 22, b. 33, c. 55, d. 27, e. 88
Example Output:
d