State How Much Larger or Smaller the First Unit Is $10 ^ { 4 }$

Multiple Choice

State how much larger or smaller the first unit is than the second.
-square decimeter, square kilometer

A) Smaller by a factor of $10 ^ { 4 }$
B) Smaller by a factor of $10 ^ { 6 }$
C) Smaller by a factor of $10 ^ { 3 }$
D) Smaller by a factor of $10 ^ { 8 }$