A hall with a 3 in. radius has volume V₁ . A second ball has a 9 in. radius and volume V₂ ' Which equation represents the volume of the second ball in terms of the first? (A) V₂ = 3 V₁ . (B) V₂ = 27 V₁ . (C) V₂ = V₁² . (D) V₂ = 9 V₁² .