In the California Insurance Code, a fact that is so important it could determine the policy premium is cited for its

Expressness pertains to the clarity and directness of the terms stated within an insurance contract. While express terms are important for defining obligations, they do not specifically address the relevance or impact of factual information on premium determination, which is the focus of the question.

Representation involves statements made by the insured that are believed to be true to the best of their knowledge. Although representations can influence the underwriting process, the term does not encapsulate the broader concept of materiality, which encompasses the overall significance of facts affecting premium rates.

Valuation refers to the process of determining the worth of an insured item or property. While valuation is crucial in setting coverage amounts and claims payments, it does not specifically relate to the importance of a fact in affecting the policy premium, which is the essence of materiality.