You are the project manager of GHT project. Your hardware vendor left you a voicemail saying that the delivery of the equipment you have ordered would not arrive on time. She wanted to give you a heads-up and asked that you return the call. Which of the following statements is TRUE?
选项：

A:This is a residual risk.
B:This is a trigger.
C:This is a contingency plan.
D:This is a secondary risk.