Hello!
The Correct Answer would be:
"Centimeter"
Considering that 49 Centimeters are Bigger or Larger than only 4 Decimeter's.
But still...remember that a Decimeter is 1/10 of a meter and a centimeter is 1/100 of a meter.
Which Obviously is Way Bigger or Larger in this Case.
Hope this Helps! Have A Wonderful Day! :)