The diagram below shows part of the rock cycle. (6 points) Rock cycle with a volcanic eruption at the top. Moving counterclockwise, there is an arrow pointing to Rock B. From Rock B there is an arrow labeled sediment and compaction pointing to Rock C. From Rock C there is an arrow labeled heat and pressure pointing to Rock A. From Rock A there is an arrow labeled magma pointing back to volcanic eruption.

Which type of rock does A represent?
Metamorphic rock
Rock formed by cooling
Rock formed by compaction
Sedimentary rock

Answer is in the photo. I can't attach it here, but I've uploaded it to a file hosting. link below! Good Luck!

cutt.ly/Kzv78uJ

Metamorphic rock

Explanation:

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.