Soot is:
Lamp black
Explanation for correct option A:
Lamp black or carbon black or soot are black particles of carbon present in flame when hydrocarbons, petroleum or substance rich in carbon content are heated in the limited supply of air. So soot is lamp black.
Explanation for incorrect
Option B:
Charcoal is formed when wood is burnt in the absence of air.It is of various wood charcoal,bone charcoal and sugar charcoal.So soot is not included in this category.
Option C:
Coke is the purest form of carbon and is produced when coal is strongly burnt in the absence of air. We get coke as a residue.
Option D:
Graphite is the allot ropy of carbon and softest mineral known with metallic lustre and greasy feel.
Thus, Lamp black or carbon black is soot when hydrocarbons,petroleum or substance rich in carbon content are heated in the limited supply of air.So soot is lamp black.