You will be given a definition of a task first, then some input of the task.
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.

Problem: average monthly income of a family of 4 earning members was rs. 840. one of the earning members died and therefore, the average income came down to rs 650. the income of the deceased was ?
Options: a. rs. 692.80, b. rs. 820, c. rs. 990, d. rs. 1410, e. none
Output:
d