If 8 persons meet at a reunion and each person shakes hands exactly once with each of the others, what is the total number of handshakes?  Choose the correct choice from the following choices
A) 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1	B) 8 × 7 × 6 × 5 × 4 × 3 × 2 × 1	C) 8 × 9	D) 28	E) 45
1st person will have 7 handshakes, 2nd will have 6, ....7th will have 1 and 8th will have 0   = 7+6+5+4+3+2+1= 
<gadget id="calculator">7+6+5+4+3+2+1</gadget>
<output>28</output>
28   if we generalize this: if there are n people then there will be n(n-1)/2 handshakes.   Ans.28)
<result>D</result>
If 8 persons meet at a reunion and each person shakes hands exactly once with each of the others, what is the total number of handshakes?