Simple...
Following Jesus's execution by the Romans, some of his earliest followers, or apostles, spread his central message by writing about his life and teachings in the New Testament.
Thus, your answer, B.
B. Opening up the eastern front
President Nixon reduced tensions between the US and the Soviet Union by traveling to China as well as the Soviet Union. When there, he signed an Arms Control Treaty with the Soviet Union in hopes of lessening the tensions.
Hope this helps!
Answer: north of the border