Use the Following Information to Answer the Question

Use the following information to answer the question. Which treatment is most effective at treating carpet stains: vinegar, ammonia, or hydrogen peroxide? In a study, researchers randomly assigned 55 carpet samples with identical stains to one of three groups. Depending on which group they were assigned to, each carpet sample received a home remedy of water mixed with vinegar, ammonia, or hydrogen peroxide. Afterwards, each carpet sample was examined and any remaining stain was measured. Researchers found that a vinegar and water mixture produced better results than both ammonia and hydrogen peroxide.
-Suppose a new engine additive is designed to improve performance in race cars and researchers wish to test the effectiveness of the new additive. On a closed race course, the individual race times for forty race cars are recorded. The race times (on the same course) for each of the cars after being
Treated with the engine additive are then recorded. Which test design would be most appropriate
For this scenario?

A) Paired t-test
B) Two-sample t-test
C) None of these