A. Only one "mouse" element can be written as a child element of the "notebook" element. W Courier Newlr Z

B. As a child element of the "computer" element, the "server" element can be written before the "notebook" element.

C. When writing the "notebook" element, "mouse" must be written as a child element.

D. Both the "notebook" element and the "server" element can be written as a child element of the computer element.