The course credit hours and grades for a student's fall semester at college are given in the table below. At the college, an A is worth six quality points, a B four points, a C two points, and a D one point. The grade-point average at the college is calculated as a weighted average, with quality points for each course weighted by the credit hours for that course. What is the student's grade-point average?

credit hours: 2. 4. 5. 3. 3. 5

grade: C. D. B. D. A. B