Trenches a. border continental and island volcanic arcs. b. result from seafloor spreading. c. are found at divergent boundaries. d. may be more than 100 km (62 miles) deep.

A) border continental and island volcanic arcs

Explanation:

Trenches refers to a type of excavation or depression in the ground that is usually deeper than it is wide, and narrow than its length. Trenches border continental and island volcanic arcs.

Trench is a word used in different professions to depicts different things:

Trenches are as a result of erosion caused by rivers or by geological movement of tectonic plates in GEOLOGY.

Trenches are created to install underground infrastructure or utilities or later to access these installations in CIVIL ENGINEERING.

Trenches can also be dug for MILITARY defensive purposes.

The "trench method" is a term used in ARCHAEOLOGY for searching and excavating ancient ruins or to dig into strata of sedimented material.