In PHP, how can you create a simple advertisement (AD) rotator without using a database, so that each page load displays one ad selected from several possible ads?

Introduction / Context:
An advertisement rotator is a common feature on websites where multiple banner images or text ads are available, and one should be displayed on each page load. When the requirement explicitly states that no database should be used, you must implement the logic using simple data structures and PHP code. This question checks whether you can describe a straightforward approach to building such a rotator using arrays and basic control flow.

Given Data / Assumptions:

• The language is PHP.
• You have multiple ads, each with an image URL and a target link.
• You are not allowed to use a database for storing ad information.
• You want one ad to be selected and displayed per page load.

Concept / Approach:
A simple data structure for this requirement is a PHP array that contains the ads. Each element can be an associative array or object with fields for image path, link, and optional alt text. On each request, the script can choose one ad from the array by using a random function or by maintaining a simple counter for round robin selection. Then the script outputs the corresponding HTML for that ad, for example an anchor tag wrapping an image tag. This approach avoids any database and keeps the implementation short and maintainable.

Step-by-Step Solution:
1. Define an array of ads in PHP, where each entry contains the URL of the banner image and the destination link. 2. Decide on a selection strategy, such as a random index using a random number function or a simple rotation based on a counter stored in a file or session. 3. On each page load, use the selection strategy to pick one entry from the array. 4. Generate the HTML to display that ad, such as an image inside an anchor tag pointing to the ad link. 5. Optionally, track impressions or clicks by logging events to a file if basic reporting is needed, still without using a database.

Verification / Alternative check:
To verify that the rotator works, you can refresh the page several times and confirm that different ads appear in the display area according to the chosen selection logic. If random selection is used, you will see ads in random order; if round robin is used, they will rotate in a fixed sequence. You do not need any database tables or queries, and the PHP code remains easy to understand and deploy.

Why Other Options Are Wrong:

• Option B is wrong because web server configuration files are not meant for rotating application level ads and would not provide a flexible selection mechanism.
• Option C is wrong because the browser cache does not decide which ad to display; it only caches resources after the server chooses them.
• Option D is wrong because creating database tables contradicts the requirement to build the rotator without using a database.

Common Pitfalls:
A common pitfall is hard coding a single ad in the template, which makes it difficult to rotate banners later. Another mistake is over engineering the solution by introducing persistent storage when simple arrays and random selection are sufficient. Developers should also take care to avoid repeating heavy file operations on every request if they log impressions, and should ensure that ad links are properly escaped to avoid security problems. For basic sites, the array based approach is often more than adequate.

Final Answer:
The correct description is By storing ad image URLs and links in an array and using a random index or round robin logic in PHP to select and output one ad on each request, because this method meets the requirement of rotating ads without relying on a database.