We are very interested in the （) mini Bluetooth earphone.

The spectrum of a continuous-time signalis, shown in the figure below. If one samples the signalat a sampling frequencyto obtain a discrete-time signal, then the spectrum of the dicrete-time signalis. Given that, which of the below spectrum is?

A、

B、

C、

D、

A. T-S-T-S

B. T-S-T

C. T-S

D. S-T-S

A、startle the audience

B、use a rhetorical question

C、tell an interesting story

D、relate the topic to the audience