In the context of Initial Public Offerings (IPO), what is the main drawback of the book-building process?

A. The fact that it may lead to overpricing of the company's shares

B. The fact that the share allocation process is not transparent and may lead to quid-pro-quo and other forms of collusion between institutional investors and underwriters

C. The fact that it may fail to attract institutional investors, thus leaving the company with few or no institutional analysts to issue recommendations on the company's shares

D. The fact that the IPO may fail due to lack of venture capitalists backing