save Question 19 (0.5 points) Which of the following statements are true? A) A blocked process is not ready to run until some condition is met B) A process may block until an 1/0 operation completes. C) A process may block until a timer expires. D) A process may block until exclusive access to a resource is obtained. E) Processes never block. O A, B, and D A,B,C, and D Only E O Only A Save 27 Question 20 (0.5 points) 32 Which of the following statements are true? 6 37 systems have user accounts to enable accounting, security, logging, and resource management per user. B) Multi-user systems correlate usernames with user IDs. 41 C) File ownership may be correlated with a user ID. D) Multi-user systems may require user login and authentication to determine authorization/permission to access system resources E) Modern versions of the Windows operating systems are roughly equivalent to a single-user, single-account systems; this means that all processes can modify the boot sector and perform other operating modifications. This enables viruses and other clandestinely installed software to integrate themselves with the operating system in a way that is difficult to detect or undo. esponse Only E 0 A. B, C, and D OA, B, D, and E ula Status A, B, C, D, and t