Which of the following statements is false?

a. A runnable thread transitions to the blocked state when it attempts to perform a task that cannot be completed immediately and it must temporarily wait until that task completes.
b. When a thread issues an input/output request, the operating system blocks the thread from executing until that I/O request completes—at that point, the blocked thread transitions to the runnable state, so it can resume execution.
c. A blocked thread cannot use a processor, even if one is available.
d. Each of the above statements is true.

d. Each of the above statements is true.