You intercepted the four ciphertexts a$)$ through d$)$ below;

you know that the original plaintexts are in English and that either a substitution cipher $($such as

the shift cipher, or the monoalphabetic substitution cipher$)$ or a transposition cipher $($such as the

skytale$)$ was used. For each ciphertext, determine whether it is the result of a substitution cipher

or a transposition cipher and explain how you reached your decision. You do not have to find

out which particular cryptosystem was used in each case $($we haven't seen most the four systems

yet$)$; in particular, you do not have to break the ciphers.

a$)$ PTNFL VPRWO FLSLV PQUPZ LMTNM MTLSL NSLCN DROZB LMMPQ BNUYO

RMNQD CTLSL DOXCN QMMOB OPZDO XSLNU UDCNQ MMOBO

b$)$ NEESU IEGOV MATUA OTLWI GERWY LLRWS TTNUI FTKOD LHNIE GIBIO

OGRTR SSITE TOFEE YNRID G

c$)$ IHIKU ORTOT TLAHC APGAB YHLRA ODATS RSYXL AWSOT SEEAI SECTN UEIOI

SOETF UEYLE TEESN NLYPP UOOCL R

d$)$ DXGVF XVGVV FVVFG GVDAX FDXFX XFFAG XVAXV DADDD XFAVX GXXGD

FVFXA FXVAV VFXGV XFVFF VVDFD AAFXF DDXFF AXFVD DDXAD DADDX

DFDAF VVDFD VDDAX GGFVA DXDGG XGDAG