What is the countermeasure for wormhole attacks?

What is the countermeasure for wormhole attacks?

A.
Authentication

B.
Longer initialization vectors

C.
TKIP

D.
Leashes

Explanation:
The countermeasure for this type of attack requires the use of
leashes, which are just data that is put into a header of the individual packets.
The leash restricts the packets maximum allowed transmission distance. The leash
can be geographical, which ensures that a packet stays within a certain distance of
the sender, or temporal, which limits the lifetime of the packet.