Which of the following queries would check for duplicates of a combined country and city in the customer table and how many there are of each?

a$.)$

SELECT country, city

FROM customer

GROUP BY country, city

HAVING COUNT$(*)>1$;

b$.)$

SELECT country, city, COUNT$(*)$

FROM customer

WHERE COUNT$(*)>1$;

c$.)$

SELECT country, city, COUNT$(*)$

FROM customer

GROUP BY country, city

HAVING COUNT$(*)>1$;

d$.)$

SELECT country, city

FROM customer

GROUP BY country, city

HAVING COUNT$(*)>0$;