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.
--------
Question: Problem: the arithmetic mean and standard deviation of a certain normal distribution are 14.5 and 1.7, respectively. what value is exactly 2 standard deviations less than the mean ?
Options: a. 10.5, b. 11, c. 11.1, d. 12, e. 12.5

Answer: c


Question: Problem: at what rate percent per annum will a sum of money double in 6 years.
Options: a. 12.5 %, b. 13.5 %, c. 11.5 %, d. 14.5 %, e. 16.6 %

Answer: e


Question: Problem: the length of the rectangular field is double its width. inside the field there is square shaped pond 9 m long. if the area of the pond is 1 / 8 of the area of the field. what is the length of the field ?
Options: a. 54, b. 36, c. 75, d. 28, e. 11

Answer:
b