For a narrow base PNP BJT , the excess minority carrier concentrations($Δn_{E}$ for emitter,$Δp_{B}$ for base ,$Δn_{c}$ for collector) normalized to equilibrium minority carrier concentrations($n_{E0}$ for emitter, , $Δp_{B0}$ for base ,$Δn_{C0}$ for collector) in the quasi-neutral emitter,base and collector regions are shown below. Which one of the following biasing modes is the transistor operating in?