Final answer:
Concurrent execution without proper management, specifically in parallel processing, can cause an inconsistent database. Parallel execution risks simultaneous access or modification to shared resources without coordination, leading to data inconsistency.
Step-by-step explanation:
When concurrent execution is not managed correctly, it can indeed lead to various issues such as data corruption or an inconsistent database. The correct answer to the question is Parallel. When processes are executed in parallel, there is a risk of them accessing or modifying shared resources at the same time without proper coordination, which can cause inconsistencies. To prevent such problems, mechanisms like locks, semaphores, or transaction control are used to ensure safe and synchronized access to databases or shared resources.