Thetemplate that will correctly display the details message only when areDetailsVisible becomes true given the following code in a Lightning Web Component is option C. Option C uses the if:true directive to conditionally render a template block based on the value of areDetailsVisible. If areDetailsVisible is true, the template block inside the <template if:true={areDetailsVisible}> tag will be rendered. Otherwise, it will be skipped. Option A is incorrect because it uses the if:false directive, which does theopposite of if:true. It renders the template block only when areDetailsVisible is false. Option B is incorrect because it uses an invalid syntax for the if directive. The if directive requires a colon (:) after the if keyword, not an equal sign (=). OptionD is incorrect because it uses an invalid syntax for the template tag. The template tag requires a closing tag (</template>), not a self-closing tag (<template/>). Salesforce References: LightningWeb Components Developer Guide: Conditional Rendering, Lightning Web Components Developer Guide: Template Syntax