Read the following conversation and answer the question.

W: It's nearly ten o'clock. Let's listen to the weather forecast.

M: Here is the weather forecast: Fog is spreading from the east and it'll affect all areas by midnight. It will be heavy in some places.

Question: What's the weather forecast? 

- There will be heavy fog in all areas.

- There will be heavy rain by midnight.

- There will be fog in all areas by midnight.


There will be fog in all areas by midnight.