How Most Often Are Shares Allocated in a Dutch Auction

How most often are shares allocated in a Dutch auction when there are more shares demanded than are available at the winning bid price?

A) Have a random draw to determine which companies will be allowed to buy shares.
B) Have a random draw to determine which companies will be excluded from buying shares.
C) Repeat the auction starting from scratch.
D) Allot each company a proportion of shares relative to the number of shares available and the number of shares demanded at the winning price.
E) Sell shares to companies with the highest bids and split the remaining shares amongst companies with bids equal to the winning bid price