Which of the following pairs is NOT correctly matched?

1. A

   Oxytocin Hormone

   (a) Oxytocin – Hormone. Correct: posterior-pituitary peptide hormone (let-down and uterine contraction).

2. B

   Aspartame Synthetic sweetener

   (b) Aspartame – Synthetic sweetener. Correct: methyl ester of a dipeptide, used as an artificial sweetener.

3. C

   Neoprene Specialized rubber

   (c) Neoprene – Specialized rubber. Correct: polychloroprene synthetic rubber.

4. D

   Rayon Modified starch

   (d) Rayon – Modified starch. Incorrect. Rayon is regenerated cellulose (viscose), not modified starch. This unmatched pair is the official key.

Summary. Official key is (d) Rayon – modified starch. Rayon is cellulose; starch is a different polysaccharide. Oxytocin, aspartame and neoprene pairs stand. Honour the stored letter (d).