In Grain Dealers Mut. Ins. Co. v. McKee, 943 S.W.2d 455, 458, 40 Tex. Sup. Ct. J. 483 (Tex. 1997), the daughter of the president and sole shareholder of the insured corporation was injured in an automobile accident while in a vehicle that was not covered by the policy. Id. The Texas Supreme Court in Grain Dealers determined that the child of the corporation's president could not be a family member of the corporation and she was not a designated person under the underinsured motorist coverage. Id. The ambiguity of an insurance policy is a question of law that must be decided by examining the policy as a whole in light of the circumstances present when the policy was entered into. See Grain Dealers Mut. Ins. Co. v. McKee, 943 S.W.2d 455, 458, 40 Tex. Sup. Ct. J. 483 (Tex. 1997). An insurance policy is not ambiguous as a matter of law if it can be given a definite or certain legal meaning. See id. Conversely, if an insurance policy is subject to more than one reasonable interpretation, the policy is ambiguous and the interpretation that most favors coverage for the insured is adopted. See id. However, ambiguity does not arise simply because the parties advance conflicting interpretations of the insurance policy. See id. A corporation's failure to name a designated person renders the policy's language regarding a "designated person" and the person's "family" inapplicable, but it does not nullify the endorsements or create ambiguity. See id. at 458-59.