Conditional Rendering is best when only one element, or a small number of elements, must be hidden or shown based on simple data logic. For example, if one field, label, icon, or block depends on a single Boolean or status value, a rendering condition is more efficient and easier to maintain than creating another FlexCard State. States are better when the card must switch to a substantially different layout or when many elements change together. Option D describes a state-level use case, not a single-element rendering condition. Option A is wrong because no condition is needed if the element is always visible. Option B is not the deciding factor; repeaters can contain conditional elements, but the reason is still the simplicity of the condition.

The Remote Action node is identified by the element name configured in the Integration Procedure. Since the Remote Action is named FetchCart, the relevant Preview JSON node for that action is FetchCart. The debug- specific node, such as FetchCartDebug, is used for diagnostic details, not as the primary action node being evaluated in this question. ResponseCart and ResponseCartDebug belong to the Response Action, not the Remote Action. Salesforce documentation confirms that a Remote Action in an Integration Procedure calls the specified Apex class, method, or invocable action, and Integration Procedure actions are configured and executed as named elements in the procedure sequence.

According to the Integration Procedure Actions page, a Remote Action can use a function in an Additional Output value field or in a Remote Options value field. According to the Response Actions page, a Response Action can use a function in an Additional Input value field.

The correct answer is A. In a parent-child FlexCard design, attributes are passed from the parent FlexCard to the child FlexCard and referenced in the child using the Parent context variable. Salesforce documentation states that the Parent context variable is used to reference attributes from the parent FlexCard on the child FlexCard, and child FlexCard properties allow passing data from the parent by creating attributes and assigning data merge field values. Therefore, when the postal code is passed as a parent attribute, the child FlexCard should reference it as {Parent.postalcode}. {Params.postalcode} is used for URL or runtime parameters, {postalcode} references local data only, and {attr.postalcode} is not the correct OmniStudio parent context syntax.

The Conditional View property on the Step elements is the correct client-side control. The branching depends on a value selected earlier in the OmniScript, and the constraint explicitly says not to use server-side logic.
Conditional View can hide or show elements, blocks, or steps based on conditions in the OmniScript data JSON. Pub/Sub on FlexCard elements is unrelated because this is an OmniScript step-visibility problem, not inter-component messaging. An Integration Procedure conditional block would push the path decision to server-side logic, violating the requirement. A Data Mapper does not control UI step visibility. Salesforce documentation states that Conditional View hides an element or group of elements in a block or step based on specified conditions, which fits this scenario precisely.