Ahem. think of it this way, what word is interjecting
Answer:
B
.The historical documents about the invention of fireworks have been lost.
Answer:
Compound sentence
Explanation:
A compound sentence is a type of sentence that contains an independent clause joined by a comma, or semicolon.
Therefore, from the given sentence, "Whenever the clock struck midnight, Cinderella lost her slipper", we can see that the sentence has an independent clause which is "Cinderella lost her slipper" which is joined to another clause with a comma.