Jacob earns $7.25 an hour at his part-time job, and earns $9 each time he mows the lawn for his mother. He graphs the amount of hours he works at his job (x) and the number of lawns he mows (y) to determine how to earn at least $300. Which type of boundary line should he use in his graph?
A A dotted boundary line, because the values on the line should not be included in the solution set.
B A solid boundary line, because the values on the line should not be included in the solution set.
C A dotted boundary line, because the values on the line should be included in the solution set.
D A solid boundary line, because the values on the line should be included in the solution set.