What is the test for an anti-SLAPP motion?

A claim arises from protected activity within the meaning of section 425.16(b)(1) if the activity underlies or forms the basis for the claim. (Park, supra, 2 Cal.5th at p. 1062; City of Cotati v. Cashman (2002) 29 Cal.4th 69, 78-79.) "Critically, 'the defendant's act underlying the plaintiff's cause of action must itself have been an act in furtherance of the right of petition or free speech.'" (Park, supra, 2 Cal.5th at p. 1063.) "In short, in ruling on an anti-SLAPP motion, courts should consider the elements of the challenged claim and what actions by the defendant supply those elements and consequently form the basis for liability." (Ibid.; see Navellier v. Sletten (2002) 29 Cal.4th 82, 89 ["In the anti-SLAPP context, the critical consideration is whether the cause of action is based on the defendant's protected free speech or petitioning activity"].)