In Aura components, the <aura:if> tag is "lazy." It does not instantiate or render the components within its body until its isTrue expression evaluates to true. In the provided code, showContactInfo is defaulted to true.
This means that when the parent component begins its initialization, it immediately starts creating and rendering the child component <c:contactInfo> simultaneously.
By changing the default for showContactInfo to "false" (Option C), the developer implements a "Lazy Loading" pattern. The parent component will load quickly because it skips the heavy lifting required to render the child. The init handler then runs, retrieves the necessary data, and sets the boolean to true only when the data is ready. This improves the "perceived performance" and the Initial Page Load time.
Option A is incorrect because it increases the complexity and weight of the parent component, likely making it slower. Option B (changing to a Map) does not fundamentally affect the rendering engine's speed. Starting with the display attribute as false ensures the browser only renders what is absolutely necessary during the critical first few milliseconds of the page load.