The question consists of three parts A$,$ B$,$ and C$.$ Solve them based on the ciphertext at the beginning of the question

make sure you solve the question step by step with explaination and also write Decrypt part with detail.. Thank you

$1.$ The ciphertext below was encrypted using a substitution cipher. Decrypt the ciphertext without knowledge of the key.

lrvmnir bpr sumvbwvr jx bpr lmiwv 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 wkbrusurbmbwjk lmird jk xjubt trmui jx ibndt wb wi kjb mk rmit bmiq bj rashmwk rmvp yjeryrkb mkd wbi iwokwxwvmkvr mkd ijyr ynib urymwk nkrashmwkrd bj ower m vjyshrbr rashmkmbwjk jkr cjnhd pmer bj lr fnmhwxwrd mkd wkiswurd bj invp mk rabrkb bpmb pr vjnhd urmvp bpr ibmbr jx rkhwopbrkrd ywkd vmsmlhr jx urvjokwgwko ijnkdhriiijnkd mkd ipmsrhrii ipmsr w dj kjb drry ytirhx bpr xwkmh mnbpjuwbt lnb yt rasruwrkvr cwbp qmbm pmi hrxb kj djnlb bpmb bpr xjhhjcwko wi bpr sujsru msshwvmbwjk mkd kbrusurbmbwjk w jxxru yt bprjuwri wk bpr pjsr bpmb bpr riirkvr jx jqwkmcmk qmumbr cwhh urymwk wkbmvb

a$.$ Compute the relative frequency of all letters A$...$Z 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.

b$.$ Decrypt the ciphertext with the help of the relative letter frequency of the English language $($see Table $1\mathrm{.}1$ in Sect. $1\mathrm{.}2\mathrm{.}2).$ 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.

c$.$ Who wrote the text?