What is the equivalent metric liquid volume unit for a cube that measures 10cm in length, 10 cm in width, and 10 cm in height? one liter one kilogram one cubic meter one meter

The answer is one liter.

The volume of the cube (V) is:
V = l · w · h            (l - length, w - width, h - height)

It is known:
l = 10 cm
w = 10 cm
h = 10 cm
Therefore:
V = 10 · 10 · 10 = 1000 cm³

1 cm³ is equivalent to 0.001 liter, therefore 1000 cm³ is:
1 cm³ : 0.001 l = 1000 cm³ : x
x = 0.001 l · 1000 cm³ ÷ 1 cm³ = 1 l

The answer should be c.

Yes you are correct use the scientific method