You need to explain the differences between an IPv4header and an IPv6 header. In this
comparison, which three statements are true? (Choose three)

A.
An IPv6 header is half the size of an IPv4 header.

B.
An IPv4 header includes a checksum. However, an IPv6 header does not include one.

C.
A router has to recompute the checksum of an IPv6 packet when decrementing the TTL.

D.
An IPv6 header is simpler and more efficient than an IPv4 header.

E.
The 128-bit IPv6 address makes the IPv6 header morecomplicated than an IPv4
header.

F.
An IPv6 header has twice as many octets as an IPv4 header.

Explanation:
The image below shows the differences between an IPv4 header and an IPv6 header:

(Reference and a good resource, too: http://www.cisco.com/web/about/ac123/ac147/archived_issues/
ipj_9-3/ipv6_internals.html)