Which type of microorganism produces $250$ grams of protein in a single day?

Consider the following four statements $(1-4)$ and select the option that includes all the correct statements:
$(1)$ The unicellular $Spirulina$ can produce large quantities of food rich in protein,minerals,vitamins,etc.
$(2)$ $Methylophilus$ $methylotrophus$,because of its high rate of biomass production and growth,can produce $25$ tonnes of protein per day.
$(3)$ Common button mushrooms are rich in Vitamin $C$.
$(4)$ Rice varieties have been developed which are rich in calcium.

Give information about $SCP$.

Which of the following is grown on a global scale to obtain Single Cell Protein $(SCP)$?

What contributes to the nutritional value of Single Cell Protein $(SCP)$?

$A$ person who is allergic to pulses was advised to take a capsule of $Spirulina$ daily. Give the reasons for the advice.