Identify the correct sentence

By time my alarm clocks rings, I have already opened my eyes.

By the time the mail arrives, she had already checked the mailbox several times.

By the time you get to work, I already completed three taks.

By the time the lunch bell rings, my stomach is already growling several times.

The correct sentence is this: By the time my alarm clocks rings, I have already opened my eyes. This sentence is grammatically correctly unlike the other options. For the other options, they are not correct because of the word choice that are used. For instance, option B ought to read like this: Before the mail arrives, she had already checked the mail box several times.