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.

[Q]: Problem: lucy bought a 1 - year, 10000 certificate of deposit that paid interest at an annual rate of 8 percent compunded semiannually. what was the total amount of interest paid on this certificate at maturity ?
Options: a. 10464, b. 864, c. 816, d. 800, e. 480
[A]: d

[Q]: Problem: if the population of a certain country increases at the rate of one person every 15 seconds, by how many persons does the population increase in 25 minutes ?
Options: a. 80, b. 100, c. 150, d. 240, e. 300
[A]: b

[Q]: Problem: a certain plant was 11 feet long on the day it was plantedthe length grows by a constant amount everyday ( inc. the first day it was planted.. if this plant grew by 30 % b / w the 4 th day and 10 th day after it was planted, how many feet per day does the plant grow
Options: a. a. 2, b. b. 4.5, c. c. 0.69, d. d. 5.5, e. e. 3
[A]:
c