Elasticity doubt

[Homer Simpson]

Which of the following is true?

a) SS and S are both elastic where SS is the more elastic supply curve
b) SS and S are both inelastic where S is the more inelastic supply curve
c) Elasticity cant be measured as supply of good is available at zero price
d) SS and S are both elastic with S as the less elastic supply curve

[Spiti]

(b) I think, because when the supply curve is vertical, it is completely inelastic, and flatter the curve, more the elasticity.