B is corrent because SysTrust was developed by the AICPA to provide evidence on the reliability of electronic systems; in a SysTrust engagement the CPA is engaged to examine whether a client maintained effective controls over the system based on Trust Services criteria that have been developed by the AICPA.
A is incorrect because it does not represent currently available services relating to systems reliability.
A is incorrect because it does not represent currently available services relating to systems reliability.
D is incorrect because it does not represent currently available services relating to systems reliability.
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