Consider a brokerage firm database with relations Holdings(AccountId, StockSymbol, CurrentPrice, Quantity) and Balance(AccountId, Balance). Write the triggers for maintaining the correctness of the account balance when stock is bought (a tuple is added to Holdings or Quantity is incremented), sold (a tuple is deleted from Holdings or Quantity is decremented), or a price change occurs.

A:Solve the problem using both row-level and statement-level triggers.

B:Give an example of a situation when row-level triggers are more appropriate for the above problem

C:and when statement-level triggers are more appropriate.