As much as C. has a partiality towards the cause of The Great War, it's most likely answer B.
The Germans declared war on the Russian Empire, guaranteed the independence of Serbia, because of their alliance backing Austria, and Serbia which the Austrians declared war on as a result of the Serbian citizen who shot the heir to the throne.
The rest of Europe's involvement was a chain reaction of countries coming to the aid of another. France with defending Russia, Britain defending Belgium, etc.
Answer:
The speed of the airplane is approximately 770 km/h (214 m/s).
Explanation:
Speed = 
Distance = 3080 km
Time = 4 hours
speed = 
= 770
speed = 770 km/h
The speed of the airplane is 770 km/h.
OR
Distance = 3080 km
But,
1 000 m = 1 km
3080 km = 3080000 m
distance = 3080000 m
Time = 4 hours
60 seconds = 1 minute
60 minutes = 1 hour
Thus, 4 hours = 60 x 60 x 4
= 14400 seconds
Therefore,
speed = 
= 213.8889
speed ≅ 214 m/s
The speed of the airplane is approximately 214 m/s.
Saddam Hussein was sworn in as president on 16/7/1979
Two mountain ranges, the Alps and the Apennines, helped to protect Rome from invasion. The Apennines divide the Italian peninsula in half and, according to SPQR Online, allowed the Romans to mass forces for counter-attack whenever they were threatened.