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: there are 6 people in the elevator. their average weight is 152 lbs. another person enters the elevator, and increases the average weight to 151 lbs. what is the weight of the 7 th person.
Options: a. 145, b. 168, c. 189, d. 190, e. 200
A:
a