Hi there! One of the sides already has a length of 8 inches. The total perimeter of the triangle is 18 inches. 18 - 8 is 10. There are 10 inches left. If the ratio is 2 : 3, then to find the other length, we see that we can divide them into fifths. 2 * 2 = 4 and 2 * 3 is 6. 4:6 has a ratio of 2:3. The length of the shortest side is 4 inches. The answer is B: 4.