The U.S. government is concerned that terrorists might try to crash a vehicle filled with explosives ...

The U.S. government is concerned that terrorists might try to crash a vehicle filled with explosives into a U.S. embassy in a foreign country. Inside the gate to the embassy, they installed steel and cement posts in the road. These posts can be raised up from the ground to form a barrier against suicide bombers. The posts can be lowered back into the ground to allow safe vehicles to pass. This physical barrier system illustrates which risk management technique?
A) risk avoidance
B) insurance transfer
C) loss prevention
D) noninsurance transfer