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: what percent is 6 gm of 1 kg ?
Options: a. 1.5 %, b. 0.5 %, c. 0.6 %, d. 3.5 %, e. 4 %
[A]: c

[Q]: Problem: a no. when divided by 281 gives a remainder 160, what remainder will be obtainedby dividingthe same no. 21 ?
Options: a. 21, b. 22, c. 23, d. 24, e. 25
[A]: a

[Q]: Problem: two guys a and b leave point a and point b simultaneously and travel towards point b and point a on the same route at their respective constant speeds. they meet along the route and immediately proceed to their respective destinations in 32 minutes and 50 minutes respectively. how long will b take to cover the entire journey between point b and point a ?
Options: a. 65, b. 90, c. 70, d. 75, e. 80
[A]:
b