It was not until she had finished all her work_____.
B
“itisnotuntilthat⋯⋯”是强调句型，“that”引导的从句用正常语序，而以“notuntil⋯⋯”开头的句子中谓语要用倒装形式。
_____alltherepresentativesstillnotthere，themeetingwaspostponedforseveralhours.
Hedidn‘tseemtomind_____themusicwhilehewasstudying.
_____youunderstandthisrule，you‘llhavenodifficultyindealingwithsuchproblems.