operating system

'111 46% 7:02 PM 21. Consider a swapping system in which memory consists of the following hole sizes in memory order: 10K, 4K, 12K, 18K, 7K, 9K, 11K, 16K, and 8K. Successive segment requests are made in the order 12K, 10K, 8K 22. Suppose Ex denotes the public key of X or the encryption (decryption) using the public key of X and Dx denotes the private key of X or the encryption (decryption) using the private key of X. If A wants to send a message M securely to B and digitally sign it, what is the correct sequence of operations? A. EA E(M)) B. EA (DB(M)) C. DA( EB ( EA(M) )) D. EB ( DA(M) ) E. DB ( DA(M))