A licensed professional, living and practicing in the province of Ontario, is charged with a...

Negligence is a tort, and tort law in Ontario is part of the common law system (judge-made law developed through precedent), supplemented by statutes where applicable. Quebec is the primary Canadian jurisdiction governed by civil law for private-law matters; Ontario is not, so A is incorrect. Public law concerns relationships between individuals and the state (constitutional, administrative, criminal), whereas a negligence claim by a former client is a private civil dispute, making B incorrect. “Regulator law system” is not a recognized legal system; regulators may discipline members, but civil courts determine tort liability and damages, so D is incorrect. NPPE materials typically test that common law applies to tort and contract claims in all provinces/territories except that Quebec’s private-law matters are governed by civil law under the Civil Code. Therefore, the applicable system in Ontario for a negligence tort claim is common law (C).