What is electron configuration? how does it work?

Electron configuration is the standard notation used to describe electronic structure of an atom. 

An atom's electron configuration is a numeric representation of its electron orbitals. Electron orbitals are differently-shaped regions around an atom's nucleus where electrons are mathematically likely to be located.

Work done = force ×distancebut force = mass ×gravityand gravity = 10m\s force = 2×10 = 20 work done = 20×3 = 60 joules

The correct answer is b