The correct answer is D. Umbrella comes from the Latin word umbra, which means “shade.”
Step-by-step explanation:
Combining two sentences commonly imply linking them by using different punctuation marks or conjunctions or including the information of the sentences being combined in a long and complex sentence. In the case of sentence 8 "Umbrella comes from the Latin word umbra" and sentence 9 "Umbra means “shade” sentence 9 just explains a section of sentence 8 which is the meaning of the Latin word.
Because of this, the correct and more simple way to combine both sentences is by using the pronoun "which" or "that" and then adding the information of sentence 9, as in option D. Therefore "Umbrella comes from the Latin word umbra, which means “shade." is the most effective way to combine the sentences, because in this way the details of both sentences are included and also the word "which" is useful to refer back to the Latin word and explain it without creating an independent sentence.