Which Statement About the Present System of Voter Registration in Texas

Which statement about the present system of voter registration in Texas is not correct?

A) The voter must register in person unless ill or disabled.
B) A parent, child, or spouse who is registered may register for the voter.
C) The voter remains registered as long as he or she remains qualified.
D) The voter may register at any time.
E) The voter is eligible to vote if registered thirty days prior to the election.