Tamlin is learning to become a carpenter. She gets paid $\$12$ per hour for building shelves and $\$14$ per hour for building cabinets. She can work a maximum of $40$ hours per week, and she would like to earn at least $\$250$ this week. Let $s$ represent the number of hours she spends building shelves and $c$ represent the number of hours she spends building cabinets. Which system of inequalities could be used to represent the given conditions?