Answer:
c) H2O and OH−
Explanation:
Acids are the species which furnish hydrogen ions in the solution or is capable of forming bonds with electron pair species as they are electron deficient species.
When an acid donates a proton, it changes into a base which is known as its conjugate base.
Bases are the species which furnish hydroxide ions in the solution or is capable of forming bonds with electron deficient species as they are electron rich species. When a base accepts a proton, it changes into a acid which is known as its conjugate acid.
The acid and the base which is only differ by absence or presence of the proton are known as acid conjugate base pair.
Thus,  for the reaction, 

The base is  and the conjugate acid of the base is
 and the conjugate acid of the base is  .
.
Also, The base is  and the conjugate acid of the base is
 and the conjugate acid of the base is  .
.
<u>Correct option is :- c) H2O and OH−</u>
 
        
             
        
        
        
Ummm I just need to answer questions sorry!!!
 
        
             
        
        
        
Answer:
Tests for gases
Hydrogen, oxygen, carbon dioxide, ammonia and chlorine can be identified using different tests.
Hydrogen. A lighted wooden splint makes a popping sound in a test tube of hydrogen.
Oxygen. A glowing wooden splint relights in a test tube of oxygen.
hope it will help
 
        
             
        
        
        
A solution is a homogeneous type of mixture of two or more substances. A solution has two parts: a solute and a solvent.