For the demand function given, find the elasticity at the given price and state whether the demand is elastic, inelastic, or whether it has unit elasticity.

$q=D(x)=800-x$;$x=45$

A$.\frac{1}{755}$; inelastic

B$.\frac{9}{151}$; elastic

C$.755$ ; elastic

D$.\frac{9}{151}$; inelastic