This Is a Certified Answer

Certified answers contain reliable, trustworthy information vouched for by a hand-picked team of experts. Brainly has millions of high quality answers, all of them carefully moderated by our most trusted community members, but certified answers are the finest of the finest.
Plate A is an oceanic crust leading plate while plate B is a continental crust leading plate because  plate A undergoes what we call as subduction process or the bending of the crust towards the mantle. 
15 3 15