The correct answer is C. mask-origin.
The mask-origin CSS property specifies the origin of a mask, which is the point from which the mask is applied to an element. The mask-origin property takes two values: top and left. The top value specifies the vertical position of the mask origin, and the left value specifies the horizontal position of the mask origin.
For example, the following CSS code will apply a mask to an element with a mask-origin of 50% 50%:
css
.element {
mask: url(https://example.com/image.png);
mask-origin: 50% 50%;
}
The mask-origin property can also be used to create masks that are not rectangular. For example, the following CSS code will create a mask that is a circle:
css
.element {
mask: url(https://example.com/image.png);
mask-origin: center center;
}
The mask-origin property is a relatively new CSS property, and it is not supported by all browsers. However, it is supported by most modern browsers, including Chrome, Firefox, Safari, and Edge.
The other options are incorrect because they do not specify the position of the mask. The mask CSS property specifies the mask itself, while the mask-position CSS property specifies the position of the mask within the element.