In their competition for power, nations raced to

create alliances.

build new colonies.

educate their citizens.

improve their quality of life.

In what instance?

But I would say build new colonies, as that is what all new nations tend to focus on

I believe the broadest answer here would be alternative B) "Build new colonies."

At first, with improvements in Navigation, explorers from most European countries raced to build new colonies, in order to expand their territory, influence, and power, by controlling mines, lands, trade routes, and providing themselves with slaves.

If the question is related to a more recent period of time, A) "Create Alliances." would also be plausible, since in more recent years, this is what countries have been doing to make sure they outdo their opposition. Having allied countries is what made World Wars I and II become World wars. Conflicts between two nations became conflicts between two groups of allies.