Need help to answer part a and b.

Here is the frequency table:

Use frequency of english letters:

Use frequency of pairs of letters

Given the below ciphertext which has been encrypted using substitution cipher, answer the following questions UZQSOVUOHXMOPVGPOZPEVSGZWSZOPFPESXUDBMETSX AIZ VUEPHZHMDZSHZOWSFPAPPDTSVPQUZWYMXUZUHSX EPYEPOPDZSZUFPOMBZWPFUPZHMDJUDTMOHMQ a) Determine the frequency of repeating the following letters in the above ciphertext. P,Z,S, W P: Hint: The frequency of the letters 'F' and 'C' in the ciphertext (in percentages) are as follows F: 3.33, C: 0.00 b. Supposed that the below figure shows the relative frequency of letters in English text. Comparing the breakdown that you find out in the partial credit 1 with the below figure, find the equivalents of plain letters for the below letters P, Z, S, W Hint: In the above ciphertext, the most common bigram is ZW, which appears three times. You can refer to the slides for finding which pair of letters has the most frequency among bigrams. In addition, notice the sequence ZWSZ in the first line. We do not know that these four letters form a complete word, but if they do, it would be another hint. nt 7 5 9 1 0 30804101 6710669212020 ett N OPQRSTUVWXYZ nt 582 20101804 22670042 tt ABCDE| F G H I J K L M Bigram Percentage Bigram Percentage TH AN ER ES EA AT EN 3.15 1.72 1.54 1.45 1.31 1.24 1.20 HE IN RE ON TI ST ND 2.51 1.69 1.48 1.45 128 1.21 1.18