Correct Option: B

Option (a), (Checksum) needs to be reorganized by each visited Router since Time to Live value is customized. Option (b), (Source Address) can't be customized by an IP router. Only NAT (Network Address Translation) can transform it. Option (c), (TTL) is decremented by each visited router. When it arrives at to zero, then packet will be rejected. Option (d), (Length) also customized whenever there is a need of performing the destruction process.