Points A, B, C, and D, in that order, lie on a line. If AB = 2 cm, AC = 5 cm, and BD = 6 cm, what is CD, in centimeters?
Choose the correct choice from the following options:
A) 1	B) 2	C) 3	D) 4	E) 5
Putting a value to each point, lets use the following:   A - 0   B - 2 (AB = 2)   C - 5 (AC = 5)   D - 8 (BD = 6)   CD is 8-5= 
<gadget id="calculator">8-5</gadget>
<output>3</output>
3.   Ans 3
<result>C</result>
Points A, B, C, and D, in that order, lie on a line. If AB = 2 cm, AC = 5 cm, and BD = 6 cm, what is CD, in centimeters?