The best concluding sentence wraps what the paragraph already said. A new example is not a close. Intro and conclusion as a set are in intro and conclusion sentences.
Restate, do not restart
If the choice would need another sentence after it, it is not a conclusion. The first-sentence version is in the best opening sentence. A hinge between paragraphs is a different leftover, in a transition at the paragraph break.
The bottom line
Close the idea. Do not open a new one in the last slot.
Start practicing
Start with a free diagnostic, then drill your weak spots with 15-question quizzes and track how you're doing across Reading, English, and Math. Compare plans whenever you're ready to go further.
This article offers general ACT prep guidance. The ACT can change from year to year, including its format, scoring, policies, test dates, and fees, so always confirm the latest details on the official ACT website at act.org before you make decisions. ACT® is a registered trademark of ACT, Inc. thirty-six is not affiliated with, endorsed by, or sponsored by ACT.