char ch;

cout << "PRESS a, b, OR c. ANY OTHER CHOICE WILL TERMINATE THIS PROGRAM." << endl;
for ( /* FOREVER */; cin >> ch; )
switch (ch) {
case 'a' : /* THE CHOICE OF a HAS ITS OWN ACTION. */
cout << endl << "Option a was selected." << endl;
break;
case 'b' : /* BOTH b AND c GET THE SAME RESULTS. */
case 'c' :
cout << endl << "Option b or c was selected." << endl;

break;
default :
cout << endl << "NOT A VALID CHOICE! Bye ..." << endl;
return(-1);
}