If i understand this correctly, it should be (M,L)
The 8th number in this sequence is -16. You are subtracting 3 between each set of numbers.
a1= 8-5= 3
a2= 5-2= 3
a3= 2-(-1)= 3
a4= -1 - (-4)= 3
a5= -4 - (-7)= 3
a6= -7 - (-10)= 3
a7= -10 - (-13)= 3
a8= -13 - (-16)= 3
ANSWER: -16
Hope this helps! :)