As we know their are several ways to find Cyclomatic complexity one of the is :
Cyclomatic complexity = Number of enclosed regions + 1
Here, +1 is because of count of external region
Therefore, Cyclomatic complexity of A is 10 (given) which means Number of enclosed regions + 1 external region
and Cyclomatic complexity of B is 10 (given) which means Number of enclosed regions + 1 external region
When we combine both the modules external region becomes same for both
Hence, 10 + 10 - 1 = 19
Option (A) is correct.