Answer:
C
Explanation:
expediency def: the quality of being convenient and practical despite possibly being improper or immoral; convenience
It doesn't make since with the sentence
 
        
             
        
        
        
The clue word "however" almost always indicates a "contrast". This is because when using this word, the writer can on one hand agree with what he or she is saying, but offer a different point of view to be considered. 
        
             
        
        
        
Actually, yes, this is true. Let's look at some examples with the word "all" to see if it agrees with verbs in singular or in plural:
All is lost
All is well
All is arranged already.
All of it is nice
This shows us that "all" agrees with verbs in singular form: the correct answer is a) True. 
        
             
        
        
        
A because sometimes one source could have more info and one could be wrong or something