Which of the following is not used for the disinfection of drinking water?

Find the mismatched pair.

Select the odd one out.

Read the following four statements $(A - D)$ and identify the two statements that contain mistakes:
$(A)$ Dough,which is used for making foods such as dosa and idli,is fermented by fungi and algae.
$(B)$ Toddy,a traditional drink of southern India,is made by fermenting sap from palms.
$(C)$ Large holes in 'Swiss cheese' are due to the production of a large amount of methane by $Propionibacterium$ $sharmanii$.
$(D)$ In our stomach,lactic acid bacteria play a very beneficial role in checking disease-causing microbes.
Which are the two statements having mistakes?

Which of the following is correctly matched?

Given below are two statements: one is labelled as Assertion $(A)$ and the other is labelled as Reason $(R)$ :
Assertion $(A)$ : $Spirulina$ is a microbe that can be used for reducing environmental pollution.
Reason $(R)$ : $Spirulina$ is a rich source of protein,carbohydrates,fats,minerals and vitamins.
In the light of the above statements,choose the most appropriate answer from the options given below: