Which of the Following Is True About Meeting the Quorum

Which of the following is true about meeting the quorum requirement at a corporate shareholders' meeting?

A) Shareholders owning the required number of shares must be present in person at the beginning of the meeting, and at the time each individual vote is taken.
B) Shareholders owning the required number of shares must be present either in person or by proxy at the beginning of the meeting, and at the time each individual vote is taken.
C) Shareholders owning the required number of shares must be present in person at the beginning of the meeting, but once the quorum is established, it exists for the entire meeting.
D) Shareholders owning the required number of shares for a quorum must be present either in person or by proxy at the beginning of the meeting, but once the quorum is established, it exists for the entire meeting.
E) Shareholders owning the required number of shares must be present either in person or by proxy for at least half the meeting in order to meet the quorum requirement.