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: if 32.5 % of the 880 students at a certain college are enrolled in biology classes, how many students at the college are not enrolled in a biology class ?
Options: a. 110, b. 330, c. 550, d. 594, e. 880
d

Problem: if the sides of a cube are in the ratio 5: 3. what is the ratio of their diagonals ?
Options: ['a. 5: 9', 'b. 9: 3', 'c. 5: 4', 'd. 3: 5', 'e. 5: 3']
e

Problem: of the 130 employees at company x, 80 are full - time, and 100 have worked at company x for at least a year. there are 20 employees at company x who aren ’ t full - time and haven ’ t worked at company x for at least a year. how many full - time employees of company x have worked at the company for at least a year ?
Options: a. 20, b. 30, c. 50, d. 80, e. 100

b