How would you determine the mobile ecommerce conversion rate for paid traffic (CPC)?

Go to Audience > Mobile > Overview. Add a secondary dimension showing Traffic type in order to see the traffic coming from paid search
Go to Acquisition > All traffic > Channels. Add a secondary dimension showing device category in order to see the paid search traffic coming from mobile
Both A and B are correct steps for determining the mobile ecommerce conversion rate for paid traffic
In Analytics you can only see traffic coming from desktop or from Mobile/tablet together. There is no way you can see mobile traffic only