The correct answer is D) scarcity of resources.
<em>The condition that motivated both, Japanese and European imperialism is a scarcity of resources.</em>
Being relatively small countries compared to other nations, Japan, Portugal, France, and Great Britain were looking for more resources for their countries. Scarcity of resources could have been one of the reasons but in reality, power, control, and dominion truly played a key role in expansionism and imperialism.
In the case of European countries, the knew that raw materials and natural resources abound in the African continent. and they wanted some of that for their monarchies. That is why they went on and invaded.