The artist Renoir's last word was "flowers," spoken as they arranged a bouquet of roses just picked from his garden in a vase on his bedroom windowsill.
1.The artist Renoir’s last word was “flowers,” spoken as they arranged a bouquet of roses just picked from his garden in a vase on his bedroom windowsill.
as they arranged a bouquet of roses just picked from his garden
as a bouquet of roses had been just picked from his garden and was being arranged
as a bouquet of roses just picked from his garden was being arranged
during the arrangement of a bouquet of roses just picked from his garden
while they arranged a bouquet of roses that had just been picked from his garden
首先,当动作发出者不确定时,首先考虑被动语态。从此可以排除A, E. "they" has no logical referent.
其次,谓语动词的并列性:完成时 "had been just picked" and "was being" can not be parallel. 排除B.
D: "during the arrangement ... " is awkward and unidiomatic. You can say this whenever you feel uncomfortable with an option and can not find a grammatical basis.