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: find the value o f 72519 x 9999 = m ?
Options: a. 434539873, b. 355797990, c. 435453490, d. m = 725117481, e. 873430134
d

Problem: find the smallest number that should be multiplied with 54000 to make it a perfect cube.
Options: ['a. 4', 'b. 5', 'c. 6', 'd. 3', 'e. 7']
a

Problem: eight machines, each working at the same constant rate, together can complete a certain job in 20 days. how many additional machines, each working at the same constant rate, will be needed to complete the job in 16 days ?
Options: a. 4, b. 6, c. 8, d. 10, e. 2

e