Question on Risk Transferrence

Which of the following is NOT a valid instance of risk transference?

Performance bonds
fixed price contracts
Use of a Cost Reimbursable contract

I would say "warranties"- because with warranty you are not transferring the risk you are waiting for the risk to happen at a later time and then you will spend the money to resolve the risk, hence the risk was never transferred, you just delayed paying for it if and when it happened.

Any suggestions, what might be the BEST answer.