Lena had $12. She bought a pack of craft paper for $6 and a sharpener for $2. Which expression correctly shows the total money Lena has left? A $12 − (−$6) + (−$2) B $12 + (−$6) − (−$2) C $12 − (−$6) − (−$2) D $12 + (−$6) + (−$2)