18. Some commercial software is closed source, meaning that the source code is not available to users. On the other hand, some software is open source, meaning that the source code is available to users. a. Give an example of software that you use (or have used) that is closed source. b. Give an example of software that you use (or have used) that is open source. c. For open source software, what can Trudy do to search for security flaws in the software? d. For closed source software, what can Trudy do to search for security flaws in the software? e. For open source software, what can Alice do to make the software more secure? f. For closed source software, what can Alice do to make the software more secure? g. Which is inherently more secure, open source software or closed source software? Why