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: if ( x - 10 ) ( y - 5 ) ( z - 2 ) = 1000 then what is the least value of x + y + z ? if x, y, z are all integer no.
Options: a. 7, b. 8, c. 9, d. 10, e. 11
[EX A]: a

[EX Q]: Problem: what is the value of n if the sum of the consecutive odd intergers r from 1 to n equals 169 ?
Options: a. 47, b. 25, c. 37, d. 33, e. 29
[EX A]: b

[EX Q]: Problem: sheela deposits rs. 5000 in bank savings account. if this is 20 % of her monthly income. what is her monthly income in ?
Options: a. 22000, b. 20000, c. 25000, d. 22235, e. none of these
[EX A]:
c