In Arizona, "if any claim alleged in the complaint is within the policy's coverage, the insurer has a duty to defend the entire suit, because it is impossible to determine the basis upon which the [insurer] will recover (if any) until the action is completed." W. Cas. & Sur. Co. v. Int'l Spas of Ariz., Inc., 130 Ariz. 76, 79, 634 P.2d 3, 6 (App. 1981). In Regal Homes, Inc. v. CNA Insurance, the insured had three primary CGL "occurrence" policy insurers during the course of four years. 217 Ariz. 159, 169, 41, 171 P.3d 610, 620 (App. 2007). Claims against the insured alleged various occurrences during the four-year period of coverage. Id. The Court held that although one of the insurers only provided coverage for one of the four years, it had a duty to defend the entirety of the underlying lawsuit. Id.