In certain high$-$cost defense contracts involving new weapons and equipment,

contracts are rarely subject to competitive bidding because:

A$)$ the government taxes the defense companies at a higher level than that of other

public sector companies

B$)$ there is an implicit agreement among defense contractors to "share contracts"

C$)$ all defense contractors have essentially the same cost structure

D$)$ no contractor is willing to assume all the risk of receiving a fixed price for the

contract