Man: I’m sorry I missed the football game, but I had a terrible cold.
Woman: You didn’t miss anything. We couldn’t have played worse.
Question: What does the woman mean().

A. She’s never watched a better game.

B. Football is her favorite pastime.

C. The game has been canceled.

D. Their team played very badly.

当一个事务访问某个数据项时，以一定的方式锁住该数据项，从而限制其他事务对该数据项的访问，这种方法称为【 】。