Identify the list that shows the rocks in increasing degrees of metamorphism (i. e., from lower to higher grade). choose one:
a. migmatite, flattened-clast conglomerate, gneiss with mica, gneiss with no mica
b. flattened-clast conglomerate, gneiss with mica, gneiss with no mica, migmatite
c. gneiss with no mica, flattened-clast conglomerate, gneiss with mica, migmatite
d. gneiss with no mica, gneiss with mica, migmatite, flattened-clast conglomerate

B. flattened-clast conglomerate, gneiss with mica, gneiss with no mica, migmatite.

The flattened-clast conglomerate is a sedimentary rock formed by sedimentation of particles in rivers, oceans, and streams. It contains pebbles, granules, boulders, and cobbles which is formed at low temperatures. Gneiss with mica is a metamorphic rock whose protolithic rock can either be a sedimentary or igneous rock.  

Example of the sedimentary protolith is sandstone while the igneous protolith is granite. It forms at temperatures as high as 320°C. As the temperature increases, mica undergoes a reaction and form other minerals resulting in gneiss without mica.

Migmatite is formed at even higher temperatures from gneiss or if gneiss comes in contact with hydrothermal fluids which lower its temperature causing it to melt. It is a metamorphic rock made up of both sedimentary and igneous rocks in partial melting conditions.