Dynamic Drop Down widget: Separate options in multiple cells in excel

how separate every option in dynamic drop down in different cell in excel report 

Unfortunately, it is not possible, the Dynamic Drop Down widget is considered as one field, which is why it is in one column and one cell in the excel file. 

However, you can set a separate for the options. In the widget settings, you can see the "Separator (Optional)" setting:

In your excel file, it will look like this:

From there, you can create a formula that would separate each item in the Dynamic Drop down column to separate cells. Here's a link on how to separate text string into columns or cells based on a delimiter: https://www.extendoffice.com/documents/excel/1786-excel-split-text-by-space.html. 

I hope that helps.