QUESTION 23 An 8-bit operating system uses 16-byte pages. Page descriptors (the entries in the page table) are represented as 8-bit integer numbers. What is the size of the unoptimized, naively implemented direct page table? (Per process.) Hint: First, calculate the maximal number of pages available to each process. 16B 256B 1024B 64B QUESTION 24 What kinds of POSIX pipes are not possible? (Check one answer) From a process to itself Between a parent process and a child process Between two sibling processes. Between any two unrelated processes ? QUESTION 25 What does the system call fork) do It starts a new program in the existing process. It checks if certain resources (forks") are available. It creates an exact copy of the caller process. It starts a new program as another process