【单选题】Click mouse on the waveform and drag it to change the pulse repetition rate or directly enter a new value of the period in the provided dialogue box , keeping the pulse width unchanged.
A.
simply type a new period value in the given dialogue box
B.
direct an entry for the new period value to the dialogue box
C.
point a straightforward new period value to the dialogue box provided
D.
enter a direction of a new period value to provide a dialogue box