A punctuation question with a joining word tests how two parts of a sentence connect. Split at the joining word: each full sentence needs a subject and main verb, with no word making it depend on the other. Two full sentences need a period, a semicolon, or a comma plus the joining word; two verbs sharing one subject need no comma. Find the boundary itself, because a nearby time word can hide where the parts meet.
Hints
- Hint 1
Start with the sentence about the dye falling out of favor. Find the subject and main verb on each side of the blank.
- Hint 2
Check the boundary between the two parts. If each side can stand alone, what does a joining word need at that boundary?
Step-by-step
Split and test the join
Step 1Test the first side
Split where but will sit, and read the left side through century, which every choice gives. Can that part stand alone? Its subject, the thing we're talking about, is The dye, and its main verb, the verb that tells what happened, is had fallen. The words about the mid-twentieth century tell when the dye lost favor, so this side is a full sentence.
- Step 2
Test the second side
On the right, what do the designers do? sustainable-fashion designers have renewed interest gives us both the subject and the main verb, so this side can stand alone too. The rest of that part tells us what they renewed interest in and why. The word recently in the choices tells when they did it, but it isn't a full sentence on its own. That time word belongs with the part about the designers, even though it comes before their subject.
- Step 3
Put the comma at the boundary
How do we join two full sentences with but? A comma must come immediately before the joining word, not later in the designers' sentence. The version with a comma after recently misses that boundary, while the semicolon after recently leaves the joining word before the designers' subject and verb. century, but recently puts the comma where the two sentences meet and leaves the second side together. Choice C.