The Advanced Research Projects Agency Network $($ARPANET$)$ is the first incarnation of what is now known as the Internet. The basic infrastructure of ARPANET consisted of several time$-$sharing host computers, packet$-$switching interface message processors $($IMPs$),$ and leased telephone lines. Can anyone tell in which year was the primitive ARPANET up and running?

A $1961$

B $1963$

C $1971$

D $1978$