The logic gate for which the output goes 'HIGH' or ' 1 ' only when an odd number of 'HIGH' or ' 1 ' are at its input, is

To get output of the following logic circuit as ' 0 ' (zero), the inputs $A, B, C$ should NOT be, respectively,

In which of the following figures, the p.n. junction diode is reverse biased?

I - V characteristics of photodiode for different illumination intensities $\mathrm{I}_1, \mathrm{I}_2, \mathrm{I}_3$ and $\mathrm{I}_4$ are drawn as follows. Then the maximum intensity among them is