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: rs. 1581 is divided among a, b and c in the ratio 10: 15: 6. what is the share of b ?
Options: a. 306, b. 765, c. 700, d. 510, e. 520
A:
a