Risk transfer refers to a type of risk processing that transfers risk to another person or unit through contract or non-contractual means. Risk transfer is the transfer of the burden of losses caused by risk. According to the above definition, which of the following is the following risk transfer? ["The hospital requires the patient's family to sign and agree before performing surgery on the critically ill patient.", 'Someone has seen a recent stock plunge, so he deposits money that would have been invested in the stock market into a bank.', 'In order to avoid the possible loss caused by the leak, Unit A requires relevant personnel to sign a confidentiality agreement.', "A company's product has a quality problem, claiming to be due to the raw material supplied by the raw material supplier being substandard."]