A punctuation question with marks in different places tests where sentences end and which words belong together. Split the text where the choices change, and test whether each side can stand alone. Read past an opening word like although, because a full sentence can follow the part it introduces. Then place each word with what it describes. Two full sentences need a period, a semicolon, or a comma plus a joining word, not a comma alone.
Hints
- Hint 1
Split the text at the blank and test whether each side can stand alone. Include the words after the comma following spectrum when you test the second side.
- Hint 2
Check what the words after the comma are doing. Does combining the three describe something, or name what yielded the image?
- Hint 3
Respectively means in the order given. Find the words it links in order.
Step-by-step
Test the sentences, then place the word
Step 1Find the first full sentence
Louis Ducos du Hauron exposed three separate negatives tells us who did something and what he did. For this punctuation question, split after the words about the filters: can that first part stand alone? Yes, it's a full sentence, because the opening words say why he did this without making it depend on another sentence.
- Step 2
Read through the although part
Does starting with although make everything after the blank unable to stand alone? No: the part introduced by although, each negative recorded only a portion of the visible spectrum, is followed by combining the three yielded a full-color image. The phrase combining the three is the subject, what yielded the image, and yielded is the main verb, which tells what happened. The comma after spectrum closes the opening although part, so the whole second part is a full sentence.
- Step 3
Place respectively
Now place respectively, which means in the order given. What does it describe? It links the three separate negatives to the filter colors red, green, and blue. Respectively belongs with how Hauron exposed the negatives, so the version with filters; respectively puts it across the sentence break from those lists.
- Step 4
Join the full sentences
A semicolon works where a period would, so it can join these full sentences. The versions with filters, respectively, although and filters respectively, although use a comma alone, which can't join full sentences. In filters, respectively; although, the comma sets off respectively, and the semicolon marks the sentence break. Choice B.