Answer:
City A is located in the Southern Hemisphere.
Explanation:
On this diagram, we can see that City A has the most daylight hours during the month of December, while the least daylight hours it has in the month of June. This means that the summer is present during December, January, and February, while winter is present during June, July, and August. This may seem strange to the majority of the people on the planet, as it is reversed from what the majority of the global population is experiencing, but the explanation is very simple.
This city is located in the Southern Hemisphere, not the Northern Hemisphere. The season in the two hemispheres doesn't occur in the same periods, but in opposing periods, so when it is summer in the Northern Hemisphere it is winter in the Southern Hemisphere, and when it's winter in the Northern Hemisphere it is summer in the Southern Hemisphere. The reason why this happens is the inclination of Earth, which results in one half of the year the Northern Hemisphere to be facing the Sun and thus get more sunlight, while in the other half of the year the Southern Hemisphere faces the Sun and gets more sunlight.