What's the solution to this problem?

Problems LL The ciphertext below was encrypted using a substitution cipher. Decrypt the ci- phertext without knowledge of the key 1rvmnir bpr sumvbwvr jx bpr 1miwv yjeryrkbi jx qmbm wi bpr xjvni mkd ymibrut jx irhx wi bpr riirkvr jx ymbinlmtmipw utn qmumbr dj w ipmhh but bj rhnvwdmbr bpr yjeryrkbi jx bpr qmbm mvvjudwko bj yt wkbrusurbmbwj k lmird jk xjubt trmui jx ibndt wb wi kjb mk rmit bmiq bj rashmwk rmvp yjeryrkb mkd wbi i wokwxwvmkvr mkd ijyr ynib urymwk nkrashmwkrd bj ower m vjyshrbr rashmkmbwjk jkr cjnhd pmer bj lr fnmhwxwrd mkd jx rkhwopbrkrd ywkd vmsmlhr jx urvjokwgwko ijnkdhrii ijnkd mkd ipmsrhrii ipmsr w dj kjb drry ytirhx bpr xwkmh mnbpjuwbt 1nb yt rasruwrkvr bpmb bpr xjhhjcwko wi bpr sujsru msshwvmbwjk mkd wkbrusurbmbwjk w jxxru yt bprjuwri wk bpr pjsr bpmb bpr cwbp qmbm pmi hrxb kj djnlb iirkvr jx jqwkmemk gmumbr cwhh urymwk wkbmvb Compute the relative frequency of all letters A..2 in the ciphertext. You may want to use a tool such as the open-source program CrypTool [50] for this task However, a paper and pencil approach is also still doable Decrypt the ciphertext with the help of the relative letter frequency of the English language (see Table 1.1 in Sect. 1.2.2). Note that the text is relatively short and that the letter frequencies in it might not perfectly align with that of general English language from the table. 3. Who wrote the text