Question

why did allied troops invade gallipoli in 1915?
○ they wanted to shore up the eastern front.
○ they wanted to break through the western front.
○ they wanted to protect shipping routes to russia.
○ they wanted to block shipping routes to germany.

Explanation:

The Gallipoli invasion in 1915 by Allied troops aimed to open a supply route to Russia (protect shipping routes to Russia) by gaining control of the Dardanelles. The eastern front was mainly involving Russia and Central Powers, and the western front was in France/Belgium, so options about shoring up eastern or breaking western front are incorrect. Blocking routes to Germany wasn't the goal here.

Answer:

C. They wanted to protect shipping routes to Russia.