Question $6-$ CRC and parity

a$)$ Assume that we are sending a message using CRC$,$ and an error occurs that

only corrupts data bits $($no CRC bits are corrupted, i$.$e$.,$ not bits in the

remainder R are corrupted$).$ Will the receiver catch all errors of this type?

If so$,$ explain why. If not, give a counter$-$example.

b$)$ Assume that we are sending a message using CRC$,$ and an error occurs that

only corrupts the CRC check bits $($i$.$e$.,$ only the bits in the remainder R$).$

Will the receiver catch all errors of this type? If so$,$ explain why. If not,

give a counter$-$example.

c$)$ Same as a$),$ except we are using parity, with the $"$p$\text{'}$s$"$ and the $"$q$\text{'}$s$"($no r$)$

d$)$ Same as b$),$ except we are using parity, with the $"$p$\text{'}$s$"$ and the $"$q$\text{'}$s$"($no r$)$ PLEASE NO AI ANSWER