Question

Which of the following weapons helped continue the stalemate on battlefields during World War I? A-Tank B-Submarine C-Fighter Plane D-Machine Gun

Answer 1

The weapon that helped continue the stalemate on battlefields during World War I is option D. Machine Gun. A stalemate is a situation in which neither side has a clear victory over the other. The war becomes very long and slow, and armies have to be creative to surprise the enemy. There were many stalemates in WWI, especially in the Western Front.  

Answer 2

The machine gun is the weapon that helped continue the stalemate on battlefield during World war I.

And as far as I am concerned, machine gun is the only weapon I found useful in the options above.