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: for the past n days, the average ( arithmetic mean ) daily production at a company was 50 units. if today ' s production of 95 units raises the average to 55 units per day, what is the value of n ?
Options: a. 6, b. 7, c. 8, d. 9, e. 10
c