A(n) forms when sediments from the ocean floor and pieces of oceanic crust are scraped from a subducting oceanic plate and adhere to an overriding tectonic plate.

a) accretionary wedge
b) deep-sea fan
c) active tectonic margin
d) submarine canyon

Option (A)

Explanation:

In terms of geology, an accretionary wedge is usually defined as the accumulation of sediments that are formed from the scraping of the subducting oceanic crust during the time of the collision. These sediments are deposited in association with the ocean floor sediments and it marks the presence of a convergent plate boundary. This takes the shape of a prism which is found at the edge of the continental plate boundary.

Thus, the correct answer is option (A).