Question: Assuming the `Horse` class exists, which is a valid example of inheritance in PHP?

1. `class Pegasus extends Horse {}`
2. `class Alicorn imports Pegasus, Unicorn {}`
3. `class Unicorn implements Horse {}`
4. `class Horse inherits Unicorn {}`

Answer: The correct answer of the above question is Option A:`class Pegasus extends Horse {}`