In Westgate, Ltd. v. State, 843 S.W.2d 448, 455 n.6 (Tex. 1992), the Court noted that "submitting alternative liability standards when the governing law is unsettled might very well be a situation where broad-form submission is not feasible." Id. Similarly, when the trial court is unsure whether it should submit a particular theory of liability, separating liability theories best serves the policy of judicial economy underlying Rule 277 by avoiding the need for a new trial when the basis for liability cannot be determined. Furthermore, Rule 277 mandates that "the court shall submit such instructions and definitions as shall be proper to enable the jury to render a verdict." TEX. R. CIV. P. 277. It is implicit in this mandate that the jury be able to base its verdict on legally valid questions and instructions. Thus, it may not be feasible to submit a single broad-form liability question that incorporates wholly separate theories of liability.