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.

Input: Consider Input: Problem: in what ratio must a grocer mix two varieties of pulses costing rs. 15 and rs. 20 per kg respectively so as to get a mixture worth rs. 16.50 per kg ?
Options: a. 3: 7, b. 5: 7, c. 7: 3, d. 7: 5, e. none

Output: c

Input: Consider Input: Problem: the shopkeeper sale, all of the prices of the items sold were different. if the price of a radio sold at the shopkeeper sale was both the 9 th highest price and the 14 th lowest price among the prices of the items sold, how many items were sold at the shopkeeper sale ?
Options: a. 23, b. 22, c. 32, d. 26, e. 17

Output: b

Input: Consider Input: Problem: 12. what is the dividend. divisor 17, the quotient is 9 and the remainder is 6.
Options: a. 150, b. 152, c. 154, d. 159, e. 144
Output: d