The volume of a rectangular prism can be found by multiplying the lengths of all three sides. So, the volume of Ashley's sandbox would be (c^3)(c^5)(4v^5) = c^(3+5)(4v^5) = c^8(4v^5) = 4c^8v^5. Therefore, the correct expression representing the volume of the sandbox is 4c^8v^5.
