Which of the Following Is an Accurate Statement Regarding Control

Which of the following is an accurate statement regarding control activities?

A) As the level of complexity of IT systems increases,the separation of duties often becomes blurred.
B) Segregation of duties would be violated if the same person authorizes the payment of a vendor's invoice and also approves the disbursement of funds to pay the bill.
C) The most important type of protective measure for safeguarding assets and records is the us of physical precautions.
D) all of the above