During metamorphism, what is the major effect of chemically active fluids?

a. increase the pressures in deeply buried, regional-metamorphic zones

b. aid in the movement of dissolved silicate ions and facilitate growth of the mineral grains

c. prevent partial melting so solid rocks can undergo very high temperature regional metamorphism

d. facilitate the formation of schistosity and gneissic banding in hornfels and slates

Option b

Explanation:

Metamorphism is the process where the variation of the geological texture resulting from the different arrangement of the minerals or the variation of minerals in protoliths, i. e., pre - existing rocks take place such that there occurs no change in state of the protolith, i. e., it does not melt into magma.

The change takes place as a result of the presence of chemically active fluids, heat and pressure.

There is a reaction between the chemically active fluid and the rock through which it passes and promotes the movement of the dissolved ions of silicate and promotes the growth of the mineral grains.