Water is
Water is a Liquid
        
             
        
        
        
Answer:
b) By mixing weak base with its conjugate acid and then adjusting the pH with strong  acid.
Explanation:
Hello,
In this case, considering that the buffer required a pH greater than 7 where the basic conditions are present, we need a weak base and its conjugate base in order to assure such pH greater than 7. Moreover, by using a strong acid, we can gently add it in order to decrease the pH up to 7.4 via a properly measured neutralization of the necessary moles of base up to a hydrogen concentration of 3.98x10⁻⁸ (pH). Therefore, answer is b) By mixing weak base with its conjugate acid and then adjusting the pH with strong  acid.
Best regards.
 
        
             
        
        
        
Yeah yeah you know where I can get it and I have to get my
        
             
        
        
        
Phylum: Chordata 
Class: Aves 
Order: Strigiformes 
Family: Strigidae 
Genus: Bubo 
Species: B. scandiacus 
from species down we have: 
species 
population 
organism 
organ system 
organ 
tissue 
cell 
organelle 
macromolecule 
molecule 
atom 
elementary particle
I hope this helps you.