The correct answer is D.
A task in a blocked state is waiting for some temporarily unavailable resource. This could be a hardware resource, such as a disk or network interface, or a software resource, such as a lock or semaphore. While a task is blocked, it is not eligible to run and is not placed in the run queues.
Option A is incorrect because a task in a blocked state is not executable. It cannot be scheduled to run until the resource it is waiting for becomes available.
Option B is incorrect because a task in a blocked state is not running. It is waiting for a resource to become available before it can run.
Option C is incorrect because a task in a blocked state does not have to be placed in the run queues. It will only be placed in the run queues when the resource it is waiting for becomes available.
Option E is incorrect because option D is the correct answer.