Anne, Markov, Peter line up at a ticket window. In how many ways can they arrange themselves so that Peter is first in line from the window? Select the correct option:
A) a 24
B) b 12
C) c 9
D) d 2
E) e 3
D   Peter's position is fixed. Now we need to arrange all others around Peter.   There are 2x1= 2 ways to arrange two people.
<result>D</result>
Anne, Markov, Peter line up at a ticket window. In how many ways can they arrange themselves so that Peter is first in line from the window?