What is democracy and why democracy?

Here is some information about four countries. Based on this information, how would you classify each of these countries. Write ‘democratic’, ‘undemocratic’ or ‘not sure’ against each of these.
a Country A: People who do not accept the country’s official religion do not have a right to vote.
b Country B: The same party has been winning elections for the last
twenty years.
c Country C: Ruling party has lost in the last three elections.
d Country D: There is no independent election commission.