Initially, $500$ units of good X were demanded at the price of $3500.$ After the price increased to $4000,$ the quantity demanded fell to $440.$ What is the elasticity of demand for good X$?$

a$.0\mathrm{.}127$

b$.0\mathrm{.}759$

c$.1\mathrm{.}021$

d$.0\mathrm{.}957$