The correct option is A Graphite is used as a dry lubricant
Graphite :
Graphite is used as a dry lubricant in machines running at high temperatures, where oil cannot be used as a lubricant.
Graphite cleaves easily between the layers; hence it is very soft and slippery.
Electrons are mobile and delocalized over the whole sheet therefore graphite conducts electricity along the sheet.
Each C atom in hexagonal ring make three sigma bonds with three neighboring C atoms and the fourth electron forms a π bond.