Which CSS property is used to set the opacity of an element?Optionstransparencyvisibilityfilteropacity

Step 1: Break Down the Problem

We need to identify which CSS property is specifically used to set the opacity of an element from the provided options.

Step 2: Relevant Concepts

1. transparency: This is not a direct CSS property but is often used to describe how see-through an element is.
2. visibility: This property controls whether an element is visible or not, but does not adjust the opacity.
3. filter: This property can be used for applying graphic effects; it can alter opacity but is not specifically for setting it.
4. opacity: This CSS property directly sets the transparency level of an element.

Step 3: Analysis and Detail

The opacity property in CSS allows you to control the transparency of an element, where a value of 1 means fully opaque, while a value of 0 means fully transparent. The values can be specified as a decimal ranging from 0.0 to 1.0.

Step 4: Verify and Summarize

The correct attribute among the options for controlling opacity is opacity. Other options do not effectively control the see-through characteristics of an element.

Final Answer

The CSS property used to set the opacity of an element is opacity.