David files a complaint for assault against Goliath. Goliath timely files a motion to dismiss for insufficient service of process. Several months later, the judge denies the motion to dismiss and notifies the parties. May Goliath, after being notified of the denial of his motion,

answer the complaint and respond on the merits to its allegations?

move to dismiss for lack of personal jurisdiction? move to dismiss for failure to state a claim upon which relief can be granted?

answer and include the defense that the complaint fails to state a claim upon which relief can be granted in the answer?

move to dismiss for lack of subject matter jurisdiction?