Answer:
A the type of dog food because it was different and every other thing was the same.
 
        
             
        
        
        
It's actually Friction.
I just did the test and got it right.
 
        
                    
             
        
        
        
Answer:
Current, I = 2.3 A
Explanation:
We have,
Voltage of the battery in a circuit is 9 volts
Resistance of the circuit is 4 ohms
It is required to find the current in a circuit. When the voltage and the resistance of the circuit is given then we can find the current in it is given by Ohm's law as :

I is electric current

or
I = 2.3 A
So, the current in the circuit is 2.3 A.