How many European states have monarch as head of state

How many European states have monarch as head of state
A: 11
B: 12
C: 13
D: 14

Europe retains multiple monarchies—kingdoms; principalities; and a grand duchy. Counting the UK; Spain; Sweden; Norway; Denmark; and others totals about twelve. Constitutional forms range from largely ceremonial to more active roles. The figure reflects common contemporary tallies.