I think it would be A, because it is moving the slowest then. But get a second opinion.
Answer:
W = 1.545E6 J total work
P = W / t = 1.545E6 J / 3 sec = 5.15E5 J/sec = 515,000 J/sec (Watts)
Using definition of power
Graphite is great lubricant because each carbon atom forms weak covalent bonds with three other carbon atoms.
Diamond and graphite both are entirely made up of carbon but both the elements are completely different because of the bonding of carbon atoms. In graphite the carbon atoms form weak covalent with the other three carbon atom due to which there is less or no force between the atoms, and makes the graphite very soft and slippery, and graphite act as lubricant.
False because opposites attract. :)