Bond yield advantage offset

[prodigal]

Kaplan Book3 Pg 106 q16.
If an Australian fund has a higher yield than New Zealand fund, why would a further increase in Australian bond yield help offset the current advantage? Why would a further decrease in NZ yield help offset the Aus advantage?
I cannot think anymore guys. What am I missing?

 

[cpk123]

increase in Aus yield means diff between aus and nz yield increases.
so the aus bond would be cheaper … in nz terms
same thing happens when nz yield drops..

 

[prodigal]

Thanks cpk.