An oil company fills 1 over 12 of a tank in 1 over 3 hour. At this rate, which expression can be used to determine how long will it take for the tank to fill completely?

1 over 12 ⋅ 3 hours

1 over 3 ⋅ 12 hours

1 over 3 ⋅ 1 over 12 hours

3 ⋅ 12 hours