4. (8 points) There are four numbers, their sum is 45. If the first number is increased by 2, the second number is decreased by 2, the third number is multiplied by 2, and the fourth number is divided by 2, the results are all the same. Therefore, the original four numbers are ( )
A. $10,10,10,10$
B. $12,8,20,5$
C. $8,12,5,20$
D. $9,11,12,13$
【Solution】Solution: Let the same result be $2 x$,
According to the problem, we have: $2 x-2+2 x+2+x+4 x=45$,
Solving for $x$ gives $x=5$,
Therefore, the original 4 numbers are $8,12,5,20$.