$(5)$ Using multimeters to make sure a diode is functioning properly is one the first things we need to do when constructing a circuit involving diodes. With a configuration as shown below, which reading is possible for the multimeter assuming the silicon diode being tested is a good one?

A$.0$ volts

B$.0\mathrm{.}685$ volts

C$.5$ volts

D$.$ None above.

$(6)$ For the NPN transistor installed on a common$-$emitter circuit board as shown below. What can be indicated from the measured voltages at the two marked positions?

A$.$ The BJT functions at cutoff.

B$.$ The BJT functions in the linear zone.

C$.$ The BJT functions at saturation.

D$.$ Cannot tell with the provided information.