What action must a defendant take to prevent losing the lack of personal jurisdiction defense?

To prevent losing the defense of lack of personal jurisdiction, a defendant must raise this objection in a timely manner in their initial pleadings, such as in the first responsive pleading or motion. This is crucial under the principles of waiving defenses; if a defendant fails to assert the defense early in the litigation, they may be deemed to have waived it.

Filing the objection in the initial pleadings ensures that the court is made aware of the jurisdictional challenge right away, allowing for appropriate legal consideration and preventing any potential prejudice to the defendant. If the defendant responds to the complaint without including this defense, or if they engage in certain actions, they may inadvertently concede to the court's jurisdiction over them.

The other options do not fulfill this requirement. For instance, including the defense in a motion for summary judgment is too late if it was not included initially, and mentioning it only during depositions does not formally notify the court or serve to protect the defendant’s rights.