Three allotropes (A),(B) and ( C) of phosphorous in the following changes are respectively.

A system undergoes the process: A to B to C to D . In this process, the change in a state function (X) of the system is x. in the steps A to B and B to C of the process, if the changes in X are y and z respectively, then the change in X in step D to C is-

Most reactive allotropic form of Phosphorous is

Allotrope of carbon among the following

The allotrope of phosphorous obtained by heating white phosphorous to 473 K is

Name three allotropes of phosphorus. Which out of these is most reactive?