Step 1: Understanding the Concept
Aspirin is a well-known analgesic and antipyretic. It is made by acetylating the phenolic OH group of salicylic acid with acetic anhydride.
Step 2: Reaction
\[ \text{Salicylic acid}+(\text{CH}_3\text{CO})_2\text{O}\to\text{Acetylsalicylic acid}+\text{CH}_3\text{COOH} \]
Step 3: Check the options
(A) Salicylic acid is the starting material, not aspirin. (C) Chloroxylenol is an antiseptic (Dettol). (D) Thymol is also an antiseptic. (B) Acetyl salicylic acid is aspirin.
Final Answer:
Aspirin is acetyl salicylic acid, option (B).
\[ \boxed{\text{Acetyl salicylic acid}} \]