answer the question Please ASAP 
The independent variable is
A: Number of friends (f) 
B: Number of cost (c) 
The dependent variable is
A: Number of friends (f) 
B: Number of cost (c) 
The equation that can be used to represent this relationship: 
A: c = 20f
B: f = 20c 
C: c = 10f
D: f = 10c
                                             
                                          
                                          
                                        
											 
			                  