Assertion (A): ARPANET was the first computer network created in the year 1969 by Advanced Research Projects Agency (ARPA) of the Pentagon, USA.

Reasoning (R): The objective of creating ARPANET was to develop a reliable communication network for the US military defence services for sending and receiving instant messages.

1. Both A and R are true and R is the correct explanation of A.
2. Both A and R are true but R is not the correct explanation of A.
3. A is true but R is false.
4. A is false but R is true.

Both A and R are true and R is the correct explanation of A.

Explanation
ARPANET, jointly designed and named by the Advanced Research Projects Agency (ARPA) and the US Department of Defense (DoD), was the first computer network and came into existence in 1969. The objective of creating ARPANET was to develop a reliable communication network for the US military defense services, enabling them to send and receive instant messages and share data.