In optical fiber communication, an $APD$ semiconductor is used for:

$A$ $p-n$ junction photodiode is fabricated from a semiconductor with a band gap of $2.5 eV$. It can detect a signal of wavelength: (Given: Planck's constant $h = 6.6 \times 10^{-34} Js$,speed of light $c = 3 \times 10^8 m/s$,elementary charge $e = 1.6 \times 10^{-19} C$)

The maximum rated power of the $LED$ is $2 \text{ mW}$ and it is used in the circuit with an input voltage of $5 \text{ V}$ as shown in the figure below. The current through resistance $R$ is $0.5 \text{ mA}$. The minimum value of the resistance $R_S$ to ensure that the $LED$ is not damaged is . . . . . . $\text{k}\Omega$.

$A$ $CCD$ camera is fabricated using a semiconducting material having a band gap of $3 \ eV$. The wavelength of light it can detect is nearly (in $nm$)

The following graph represents:

Given below are two statements: one is labelled as Assertion $A$ and the other is labelled as Reason $R$.
Assertion $A$: Photodiodes are preferably operated in reverse bias condition for light intensity measurement.
Reason $R$: The current in the forward bias is more than the current in the reverse bias for a $p-n$ junction diode.
In the light of the above statements,choose the correct answer from the options given below: