New to the web scraping world. Have learned to scrape contents from webpages with drop-down menus here. However, I met webpages have multiple drop-down menus. I cannot use the select option to locate the right attribute. Moreover, sometimes there may have duplicate results. 
The example page is listed below:
https://www.euromarc.co.nz/itemdetails/Elite-Cutting-Disc-905/423.aspx
My sitemap:
{"_id":"grinding_discs","startUrl":["https://www.euromarc.co.nz/category/Grinding-Discs/213.aspx"],"selectors":[{"id":"product","type":"SelectorLink","parentSelectors":["_root"],"selector":"a.product-name","multiple":true,"delay":0},{"id":"size","type":"SelectorElementClick","parentSelectors":["product"],"selector":"body","multiple":true,"delay":2000,"clickElementSelector":"div.row select option","clickType":"clickOnce","discardInitialElements":"discard-when-click-element-exists","clickElementUniquenessType":"uniqueCSSSelector"},{"id":"singleprice","type":"SelectorText","parentSelectors":["size"],"selector":"div.currentPrice","multiple":false,"regex":"","delay":0},{"id":"qty1","type":"SelectorText","parentSelectors":["size"],"selector":"#ctl00_ctl00_MainContent_uxProduct_uxProductPriceBreaks_pnlBreaks span:nth-of-type(1)","multiple":false,"regex":"","delay":0},{"id":"qty2","type":"SelectorText","parentSelectors":["size"],"selector":"p span:nth-of-type(2)","multiple":false,"regex":"","delay":0},{"id":"chosen_size","type":"SelectorText","parentSelectors":["size"],"selector":"div.row select option[selected]","multiple":false,"regex":"","delay":0}]}