Pick out the correct statement pertaining to Venturimeter.

A Venturimeter with a fixed pressure drop discharges more, when the flow is vertically downward, than when the flow is vertically upward

The co$-$efficient of contraction of a Venturimeter is always unity

For a fixed pressure drop, the discharge of a gas through a Venturimeter is greater, when compressibility is taken into account, than when it is neglected

None of these