On your OS X computer, you want the Finder to display filename extensions by default. How can you configure this setting?
A. Choose Show View Options from the View menu in the Finder, and select the option "Show all filename extensions."
B. Choose Preferences from the Finder menu, click Advanced, and select the option "Show all filename extensions."
C. Control-click anywhere on the Desktop, select Preferences from the pop-up menu, and select the option "Show all filename extensions."
D. Choose Get Info from the File menu; click the disclosure triangle next to Name & Extension, deselect "Hide extension," and click Change All.