how selenium select the option from dropdown list when there have no options

i am trying to use python+selenium to get the dropdown list options, but I found there have no options in the source code and the elements. so I do see the options from my browser, like this

but when I inspect it, i only found this

I just want selenium could hlep me click the the options, and i also record that, the recoders using xpath method to find the element , but now it cannot found it ,

driver.find_element_by_xpath("(.//*[normalize-space(text()) and normalize-space(.)='DN 80 (3 in.)'])[1]/following::td[5]").click() 

I know it is wrong , but what should i do to select the different options,