Mutation and Type$-$Flaw Attacks

Consider the following $4-$message protocol between A and B$,$ where $($N$+1)$ represents the increment of the number N:

$1.$ A$->$B: $($A$,\{$NA$\}$KAB$)$

$2.$ B$->$A: $\{($NA$+1,$ NB$)\}$KAB

$3.$ A$->$B: $\{$NB$+1\}$KAB

$4.$ B$->$A: $\{($K$$AB$,$ NA$)\}$KAB

Which one of the following mutations to messages of the protocol above, would constitute a

harmful attack:

a$)1.$ A$->$B: $($C$,\{$NA$\}$KAB$)$

b$)1.$ A$->$B: $(\{$NA$\}$KAB$,$ A$)$

c$)4.$ B$->$A: $\{($KAB$,$ NA$)\}$KAB

d$)4.$ B$->$A: $\{($K$$AB$,$ NB$+1)\}$KAB

e$)3.$ A$->$B: $\{$NB$+1\}$KpbB

f$)2.$ B$->$A: $\{($NA$+1,$ NA$)\}$KAB