Step 1: Read the chain of statements.
The first statement says all medicines are drugs. The second says all drugs are chemicals.
Step 2: Connect the two groups.
If every medicine belongs to the group of drugs, and every drug belongs to the group of chemicals, then every medicine must also belong to the group of chemicals.
Step 3: Identify the reasoning.
The conclusion follows correctly by deductive reasoning.
\[ oxed{ ext{Option 1}} \]