Option (d)
It is given that A,B and C can take values ≥0
Give values to C from 0
At C=0, the equation changes to A+B=10. Number of solutions will be based on
arrangement of 10 zeroes and 1 one = 11C1 = 11
At C=1, the equation changes to A+B=7. Number of solutions=8C1 =8
At C=2, the equation changes to A+B=4. Number of solutions= 5C1 =5
At C=3, the equation changes to A+B=1. Number of solutions= 2C1 =2
Total number of solutions = 11+8+5+2 = 26