At the first track meet, Bobby threw the shot put feet. At the second track meet he threw the shot put feet.
Which of the following expressions could be used to find the distance he improved his throw from the first track meet to the second track meet?
A. 423/4 + 44 1/2
B. 42 3/4 - ( -44 1/2 )
C. 44 1/2 - ( 42 3/4 )
D. 42 3/4 - 44 1/2