Please give me the answer with a detailed explanation.

What are some of the reasons for underpricing in the IPO?

1 There is asymmetrical information. 2 It is not clear what price the market is willing to pay 3 It's a way to market the shares 4 The underwriter wants to maintain good relationships with their pool of investors. a. 1 only b. 2 and 3 c. 4 only d. All of the above