Which of the following is possible when software is licensed under the FSF General Public License (GPL)?

Select one:

a. Users can edit and redistribute the software, as long as their changes are also licensed under the GPL

b. Anyone who receives the software can replace the license with something they prefer, like the BSD or MIT licenses

c. Users can print using the software, but only on GPL-licensed printers

d. Programmers can create educational software, which under Australian law must be licensed under the GPL