Answer:
Autumn.
Step-by-step explanation:
The Northern and Southern Hemispheres are flipped. This means that when it's summer in the Northern Hemisphere, it will be winter in the Southern.
Let's write out a quick season list:
Northern Hemisphere: Spring, Summer, Autumn, Winter
Now, the Southern Hemisphere is reversed: Autumn, Winter, Spring, Summer
March lies around the Spring season, so when it's Spring in the Northern Hemisphere, it will be Autumn in the Southern Hemisphere.