If a base class pointer, p, points to a derived class instance, and both base and derived classes have a method void doIt() which takes no parameters, then p->doIt() will invoke the derived class version: a. only if both the base class method and the derived class method are declared virtual.
b. if the derived class method is declared virtual, but the base is not declared virtual.
c. if the base class method is declared virtual, even if the derived class method is not declared virtual.

Which of the following methods could be considered a “best practice” in terms of informing respondents how their answers to an on-line survey about personal information will be protected? respondents are informed that investigators will try to keep their participation confidential; however, confidentiality cannot be assured. respondents are informed that a research assistant will transfer all the research data to a password-protected computer that is not connected to the internet, via a usb flashdrive. the computer is located in a research team member’s office. the investigator uses the informed consent process to explain her institution’s method for guaranteeing absolute confidentiality of research data. the investigator uses the informed consent process to explain how respondent data will be transmitted from the website to his encrypted database without ever recording respondents’ ip addresses, but explains that on the internet confidentiality cannot be absolutely guaranteed.

Ihave a music player on my phone. i can buy songs, add them to playlists and play them. obviously it would be redundant to store each song in each playlist; each playlist is just a list of pointers to the songs. for this lab you will simulate this behavior. your program will need to have options to: add songs to the system library (you will store the text of the first line of the song, rather than the audio) add playlists add songs to a playlist list playlists play a playlist list all of the songs in the library with a count of how many times each song has been played remove a song from a playlist remove a playlist remove a song from the library (and thus from all playlists that contain it) note that we will not be checking many error cases. in real programming this would be bad, you should usually try to recognize and respond to as many types of errors as you can. in the context of class we are trying to acquaint you with as many concepts as possible, so for the sake of educational efficiency we will not be checking most errors in this lab, you may assume that your user provides correct input. you may add all appropriate error testing if you wish, but we will not be testing for it.

Per the municipal solid waste report, what are the most common sources of waste (trash