Match the column

Column-I	Column-II
(A) Acetobacter aceti	(i) Citric acid
(B) Clostridium butylicum	(ii) Lactic acid
(C) Aspergillus niger	(iii) Acetic acid
(D) Lactobacillus	(iv) Butyric acid

(A) A-(ii), B-(i), C-(iii), D-(iv)
(B) A-(iii), B-(ii), C-(i), D-(iv)
(C) A-(iii), B-(iv), C-(i), D-(ii)
(D) A-(iv), B-(iii), C-(ii), D-(i)

Hint: We can predict the acid related with the given microorganisms by their name also. Lactobacillus converts sugars to an acid and this acid is found in most of the milk products.

Complete Step-by-Step Solution:
We will find the acid related to the given bacteria.
- We know that Acetobacter aceti is a gram negative type of bacteria. It however converts ethanol to acetic acid. It is also used commercially in the production of vinegar from ethanol. Thus, as the name suggests, Acetobacter aceti is related with acetic acid. So, (A) in column-I is related with (iii) in column-II.
- Clostridium butylicum is a gram positive type of bacteria. It is responsible for the production of butyric acid. Thus, in this case also as the name suggests, Clostridium butylicum is related with butyric acid. So, (B) in column-I is related with (iv) in column-II.
- Aspergillus niger is a kind of fungi. It is used in industries to produce citric acid and gluconic acid. This is done by the fermentation process. Thus, Aspergillus niger is related with citric acid. So, (C) in column-I is related with (i) in column-II.
- Lactobacillus is a bacteria species. They are responsible for the production of lactic acid in our body. They produce lactic acid from sugars.

Thus, (D) in column-I is related with (ii) in column-II. So, we can say that the correct match of column-I and column-II is A-(iii), B-(iv), C-(i), D-(ii).

Therefore, the correct answer is (C).

Note: Remember that Aspergillus niger is not only used for the production of Citric acid but gluconic acid is also produced with its use in many industries. All the bacteria produce the acids as a result of the process called fermentation.