Single Cell Protein $(SCP)$ is obtained through which process?

Give information about $SCP$.

$S$ - Statement: Heterotrophic mushrooms are cultivated globally.
$R$ - Reason: $A$ $250 \ kg$ cow produces $200 \ kg$ of protein daily.

How much protein can a methylotroph like Methylophilus methylotrophus produce in a single day?

Consider the following four statements $(A-D)$ and select the option which includes all the correct ones only.
$(A)$ Single cell $Spirulina$ can produce large quantities of food rich in protein,minerals,vitamins,etc.
$(B)$ Body weight-wise,the microorganism $Methylophilus$ $methylotrophus$ may be able to produce several times more proteins than the cows per day.
$(C)$ Common button mushrooms are a very rich source of vitamin $C$.
$(D)$ $A$ rice variety has been developed which is very rich in calcium.

Consider the following statements $(I-IV)$ and select the option containing the correct answer.
$I.$ The unicellular $Spirulina$ can produce large quantities of food rich in protein,minerals,and vitamins.
$II.$ Based on body weight,the microorganism $Methylophilus$ $methylotrophus$ can produce much more protein in a day than a cow.
$III.$ Common button mushrooms are a rich source of Vitamin-$C$.
$IV.$ $A$ variety of rice has been developed that is rich in calcium.