Karen is making a large salad for a party. She buys lettuce for $2 per pound and tomatoes for $3 per pound. She spends at least $13. Let x represent the number of pounds of lettuce that Karen buys. Let y represent the number of pounds of tomatoes that Karen buys. Which inequality represents this situation?
2x + 3y ≤ 13
2x - 3y < 13
2x + 3y > 13
2x + 3y ≥ 13