Question

What was the main reason imperial nations built large naval forces? to initiate sea-based attacks on other nations to demonstrate their size and prowess to protect their economic interests to resist attacks on their harbors

Answer 1

The main reason why imperial nations built large naval forces was to "to protect their economic interests" since the longer the reach of a nation, the more vulnerable it was. 

Answer 2

the answer would be B to demonstrate their size and prowess.

many nations during the imperialistic era were also very nationalist and believed they had to prove their strength to other nations. this nationalism and build up of military powers in europe also contributed to the start of world war 1