Point a on a Production Possibilities Curve,where Bicycles Are on the Vertical

Multiple Choice

Point A on a production possibilities curve,where bicycles are on the vertical axis and tricycles on the horizontal axis,represents a combination of 10 bicycles and 4 tricycles,and point B represents 6 bicycles and 6 tricycles.The absolute value of the slope of the production possibilities curve between points A and B equals

A) 2.
B) 4.
C) ½.
D) ¼.
E) 6.