Well it depends on what you are talking about.
I think the answer is either a or c
<span>The islands that were not well defended and after
taking the islands, General MacArthur would use air power to cut supply lines and
starve enemy troops, and thus it being called Island hopping.
</span>
<span> D. The German use of unrestricted submarine warfare
Hope this Helps:)</span>
Answer:
I'd say the telegraph.
Explanation:
Developed in the 1830s and 1840s by Samuel Morse (1791-1872) and other inventors, the telegraph revolutionized long-distance communication.
