Which aircraft is manufactured by Lockheed and referred to as the "Viking"?

The aircraft known as the "Viking" is the S-3, manufactured by Lockheed. This designation stems from its primary role in anti-submarine warfare and maritime patrol missions. The S-3 Viking was designed to improve the United States Navy's capabilities in detecting and engaging submarines, and its design incorporated advanced radar and sonar equipment to fulfill this mission.

In contrast, the other options refer to different aircraft that serve distinct purposes. The P-3 Orion is a maritime surveillance aircraft but is not referred to as the "Viking." The T-34 Mentor is a military trainer aircraft, and the T-2 Buckeye is another type of trainer aircraft used primarily by the Navy. These other aircraft have their own designations and roles, but they are not known as the "Viking."