Zener Diode

During regulation action of a Zener diode correct statement is :- (a) the current and voltage across the Zener remains fixed. (b) the current through the series resistance (RS) changes. (c) the Zener resistance is constant. (d) the resistance offered by the Zener diode changes.

A zener-regulated power supply consists of a 9 V battery connected in series with a resistance of 100 Omega and a zener diode. The zener diode maintains a constant voltage drop of 4 V across a load resistance of 400 Omega . The current drawn by the load resistance will be