If the inflation rate in New Zealand rises relative to the inflation rate in Australia, the most likely effect would be that demand for Australian goods will rise.
This is because as inflation rises in New Zealand, prices of goods and services in New Zealand would tend to increase, making New Zealand goods relatively more expensive compared to Australian goods. As a result, consumers and businesses in New Zealand might turn to Australian goods, which would then increase the demand for those goods.
So the correct response would be:
Demand for Australian goods will rise.