Astudent is running a 3-kilometer race. he runs 1 kilometer every 2 minutes. select the function that describes his distance from the finish line.

X - number of minutes;
f ( x ) - the distance from the finish line.
   x :        0     2      4      6
f ( x ) :    3      2      1     0
f ( x ) = 3 - x/2
B ) f ( x ) = -1/2 x + 3