Use Time Data processing before computing frequency response

 determines if the processing of the Time Data plot type is to be applied before computing the frequency response. Note that if this is not checked, the DC-component is automatically removed.

Click the  button to open the settings for the Time Data plot type, as shown below.

Only the Time Data Processing settings are enabled since the other settings have no effect in the frequency domain. This dialog box is explained in the Plot->Plot Type Settings->Time Data.... reference documentation.