Refer to the exhibit. The Linksys router in the diagram is performing pNAT (port network address translation). What hash algorithm should you choose and why?（）

• A、Use hash MD5 to ensure that IKE works through NAT. 
• B、Use ah-sha-hmac, as it does not check the integrity of the IP header. The IP header will change due to NAT. 
• C、Use 3DES, as it will encrypt the IPSec header IP addresses and bypass addressing issues. 
• D、Use esp-sha-hmac, as it does not check the integrity of the IP header. The IP header will change due to NAT.