Your Answer would be A I believe.
 
        
             
        
        
        
Answer:
how many people were asked though
Explanation:
 
        
             
        
        
        
I say the answers is A but if you mean ventilation in the area of the room then answer B
        
                    
             
        
        
        
Answer:
A) True  
Explanation:
Yes this is true when length is creases the heat transfer coefficient decease with length.
The heat transfer(h) coefficient is varying with x by given expression
For Laminar flow

For turbulent flow

But when flow is in transitional state the heat heat transfer(h) coefficient is increases with x.But for laminar as well as turbulent flow h is decrease when x increases. 
 
        
             
        
        
        
Answer:
Explanation:
The detailed steps is as shown in the attachment.