How is a button group implemented in Python Programming? (a) Each radio button in a group has a different value but all the buttons in the group use a same variable (b) Each radio button in a group has a same value, and all the buttons in the group use a same variable (c) Each radio buton in a group has a different value and a different variable (d) Each radio button in a group has a same value but a different variable Which is the ans?