Answer:

(B.)_6

Step-by-step explanation:

As the right hand digit of the sum of A+B+C=C,

it means that A+B=10 so A or B, none can be 0.

Also, the sum of A+B+C can not exceed 19.

So, 1 is carried to the second column.

Now, 1+A+B+C gives A as the right digit of the sum.

So, A=C+1.

Further, again 1 is carried over to the third column as A

cannot be 0 and the sum of 1+A+B+C can be at most 19.

On adding A+B+C+1 we get BA, thus here B=1.

Using A+B=10,A=10−1=9

Also, A=C+1

⇒C=A−1=9−1=8.

So, A=9,B=1 and C=8 satisfy all the conditions.