The 4th term of the sequence can be determined as,

Thus, option (b) is correct.
 
        
             
        
        
        
An= A1 r ^(n-1)
An= -4 (-3)^(n-1)
An= -4 (-3)^(7-1)
An= -4 (729)
An= -2916
I think this is right :)
        
             
        
        
        
It's the first one and the last one need any more help let me know okay