In the Context of Stock Ownership,what Is Meant by Backdating

In the context of stock ownership,what is meant by backdating a stock option?

A) Reaping windfall in the stock market by selling stock based on company's nonpublic information
B) Falsifying numbers in the company's annual report to hide losses and inflate the stock prices
C) Buying company's stock just before the date of key product launch
D) Changing the price in the original option agreement so that the option holder can buy stock at a bargain price
E) Re-evaluating a company's stocks to adjust it to a previous date so that the shareholders and employees minimize the losses