Select the option that will correctly replace the question mark (?) in the series.107, 103, 87, 51, ?

Select the option that will correctly replace the question mark (?) in

1.	Select the option that will correctly replace the question mark (?) in the series.107, 103, 87, 51, ?
A.	-13
B.	15
C.	13
D.	-15
Answer» B. 15