Which of the following font-weight property make the text lighter in relation to its parent?

The correct answer is C. lighter.

The font-weight property is used to specify the weight of a font. The weight of a font can be normal, bold, lighter, or heavier. The lighter keyword makes the text lighter in relation to its parent. The normal keyword sets the font weight to the default value, which is usually normal. The bold keyword makes the text bolder. The heavier keyword makes the text heavier.

Here is an example of how to use the font-weight property:

p {
font-weight: lighter;
}

This code will make the text in all paragraphs lighter in relation to their parent elements.