Correct answer is : C

"&" is bit wise AND operator.
23 and 26 will be converted to binary form i.e. 10111 and 11010 respectively and then python performs bit wise AND operation.

23 & 26 Result
1 AND 1 1
0 AND 1 0
1 AND 0 0
1 AND 1 1
1 AND 0 0

Then binary 10010 results in 18