Answer:
A
Step-by-step explanation: just divide 71 into 2 which gives you 35.5 making a your answer.
Given the points A and B
The coordinates of point A = ( 3 , 1 )
The coordinates of point B = (-1 , -1)
The midpoint of AB, is the point C
C will be calculated as following :

so, the midpoint of AB = (1 , 0 )