Which query would be more efficient?

$1.$ SELECT $*$

FROM customer

WHERE city IN

$($SELECT city

FROM employee

WHERE reports$\_$to $=2)$;

$2.$ SELECT customer.$*$

FROM customer

INNER JOIN employee

ON customer.city $=$ employee.city

WHERE reports$\_$to $=2$;

Query #$2$ would be more efficient as it is based on primary and foreign keys.

Both would be the same as both use the same indices for the join and filter.

Query #$1$ would be more efficient as it is based on primary and foreign keys.

Query #$1$ would be more efficient as it is not using indexed columns.