Answer :

I'm not sure if that's exactly what you mean, but if the scale of the drawing is 10cm:1mm, it means that 10cm of the drawing represents 1mm of the actual object. So the scale drawing is bigger than the object.
The correct answer is:

The scale drawing is larger.


A scale for a scale drawing is written as a ratio in the form
(scale size):(actual size).  

For example, on a map you may have a scale that says 1 in: 2 mi.  This means that 1 inch on the scale is equal to 2 miles on the map.

The scale for this problem is 10 cm: 1 mm.  This means that 10 cm on the scale drawing represents 1 mm on the actual object.

10 cm is larger than 1 mm, so the scale drawing is larger.