HTML and CSS Certification Practice Test

The choice that correctly sets the background image to cover the entire background area is indeed the first one. By using the declaration `background: url(flower.jpg);`, it specifies the image to be used as the background for the selected element. The subsequent declaration, `background-size: cover;`, plays a crucial role as it ensures that the background image will scale to cover the entire background area of the element, regardless of its dimensions. This means that the image will fill the space while maintaining its aspect ratio, which prevents distortion and ensures a visually appealing layout.

The other options do not implement the correct syntax or properties for achieving a full background coverage. For instance, the second choice incorrectly uses `size: cover;` instead of the correct `background-size` property, which results in the style not being applied as intended. Similarly, the third option lacks the proper syntax to identify the image as a background and also misuses the `size` property, which is not a valid CSS property in this context. Lastly, the fourth option also incorrectly employs `size: fill;`, a property that does not exist in standard CSS. Therefore, the first option stands out as the only correct answer for setting a background image to cover the entire area.