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: last year elaine spent 20 % of her annual earnings on rent. this year she earned 35 % more than last year and she spent 30 % of her annual earnings on rent. the amount she spent on rent this year is what percent of the amount spent on rent last year ?
Options: a. 202.5, b. 194.5, c. 197.5, d. 182.5, e. 177.5
a

Problem: find the area of a parallelogram with base 10 cm and height 20 cm.
Options: a. 200, b. 384, c. 200, d. 244, e. 242
c

Problem: the age of somu is one - third his father ' s. 6 years back he was one - fifth of his father ' s age. what is his persent age ?
Options: a. 11, b. 13, c. 14, d. 12, e. 10

d