Which of the following have been offered as justification for IPO underpricing?

I. Young firms tend to be very risky.

II. The best IPOs are oversubscribed.

III. Underwriters like to avoid lawsuits.

IV. Underpricing benefits the existing shareholders.

I, II, and III only

II and IV only

I and III only

II, III, and IV only

I, II, III, and IV