Answer:
B. Square hectare
Step-by-step explanation:
A square centimeter is about the size of an adult's thumb fingernail.
A square hectare is about the size of a football field.
A square meter is about the size of two king sized pillows put together into the shape of a square.
A square millimeter is smaller than the eraser on a #2 pencil.
Because you want to use a unit of measurement that is efficient for measuring something very large, you would use a hectare.