Critical Reasoning (CR) | Re: Guillemots are birds of Arctic regions. They feed on fish

My issue with (D): what if, in spite of the thin ice in the southern Arctic disappearing, the guilletmots' range expands so far up north that the loss of thin ice in the south Arctic is insignificant?

the way i see it, there are a few possible ways to decrease the # of guillemots: 1) increase # of predators; 2) decrease food supply. i don't see how 1 can be preferred over the other. they're equally dangerous.

please help

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