Explanation:

Here are explanations of the given word and options:

- Toxic: Refers to something harmful, poisonous, or dangerous to health or the environment.

- Option 1: Healthy:

- Represents something beneficial, safe, or good for health.

- Antonym of "toxic."

- Option 2: Venomous:

- Similar to "toxic," it means capable of injecting poison or harmful substances.

- Not an antonym.

- Option 3: Lethal:

- Indicating something deadly or fatal.

- Similar in context to "toxic," not an opposite.

- Option 4: Harmful:

- Means causing damage or adverse effects.

- Closely related to "toxic," not an antonym.