Final answer:
The Drive to Defend, option D, is the reactive drive in the Four-drive Theory. It is triggered in response to threats to what one values, unlike the other proactive drives.
Step-by-step explanation:
The drive that is reactive rather than proactive in the Four-drive Theory is D. Drive to Defend. The Four-drive Theory suggests that humans have four basic motivational drives: the Drive to Acquire, which is the desire to own and collect goods; the Drive to Bond, which is the need for social relationships and emotional closeness; the Drive to Create, which is the urge to innovate and produce; and the Drive to Defend, which is the necessity to protect what we care about, such as our relationships, accomplishments, and possessions.
This last drive, the Drive to Defend, is reactive in nature because it typically gets triggered in response to a threat or challenge to what we value or have already established, whereas the other drives can lead us to chase personal or inherently proactive goals.