Sentence Correction - Litesee.com Test - 3

The sale of government surplus machinery will begin at 9 a.m. and continue until the supply lasts.

A will begin at 9 a.m. and continue until the supply lasts
B begins at 9 a.m., continuing until the supply lasts
C will begin at 9 a.m. and, until the supply lasts, will continue
D begins at 9 a.m. and, as long as the supply may last, it continues
E will begin at 9 a.m. and continue as long as the supply lasts

Source: Litesee.com - Test 3 - Question 1.
Ans: E

What is the difference between "Until" and "as long as"?
Please help me with this question.

Thanks