The system tool that rearranges files and unused space on the hard drive so programs can run faster is
a. disk cleanup.
b. system information.
c. disk defragmenter.
d. compression agent.

Write an application that allows a user to enter the names and birthdates of up to 10 friends. continue to prompt the user for names and birthdates until the user enters the sentinel value “zzz” for a name or has entered 10 names, whichever comes first. when the user is finished entering names, produce a count of how many names were entered, and then display the names. in a loop, continuously ask the user to type one of the names and display the corresponding birthdate or an error message if the name has not been previously entered. the loop continues until the user enters “zzz” for a name. save the application as birthdayreminder.java.