Aseries of volcanoes make up the range.
a.
sierra nevada
b.
appalachian
c.
alaskan
d.
cascade

A series of volcanoes make up the Cascade Range. To be more specific, it includes the notable volcanoes known as the High Cascades. It also includes non-volcanic mountains such as the North Cascades. The Cascade Range is a major mountain range of western North America extending from southern British Columbia through Washington and Oregon to Northern California.

Brand c i think that should be it