Teacher: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.
Teacher: Now, understand the problem? Solve this instance: Problem: if a farmer wants to plough a farm field on time, he must plough 120 hectares a day. for technical reasons he ploughed only 85 hectares a day, hence he had to plough 2 more days than he planned and he still has 40 hectares left. what is the area of the farm field and how many days the farmer planned to work initially ?
Options: a. 600, b. 490, c. 720, d. 435, e. 679
Student:
c