Is there a way to have the first item in a data validation drop-down list automatically selected?

I have a workbook set up with dependent lists data validation. So I enter the first cells data, 5:30 PM. The second cell's data validation is always the first cell's time + two hours. Instead of clicking the drop-down list and selecting the only option, 7:30 PM, is there a way to have the value selected automatically?

Thanks!