The health check mechanism of HUAWEI CLOUD ELB can identify whether there are unavailable ECS instances in the back-end server group. If there are, these abnormal ECS instances will not be assigned tasks until these ECS instances return to normal. However, in some special application scenarios, the health check needs to be turned off. Which of the following descriptions about turning off the health check is correct?

The health check mechanism of HUAWEI CLOUD ELB can identify whether there are unavailable ECS instances in the back-end server group. If there are, these abnormal ECS instances will not be assigned tasks until these ECS instances return to normal. However, in some special application scenarios, the health check needs to be turned off. Which of the following descriptions about turning off the health check is correct?
A . The health check cannot be closed on the fourth and seventh floors.
B . The health check can be turned off for the seventh layer service, but the health check cannot be turned off for the fourth layer service.
C . Both the fourth and seventh floors can close the health check.
D . The health check can be turned off for the fourth layer service, but the health check cannot be turned off for the seventh layer service.

Answer: C