Choose the appropriate preposition to fill in the blank:

It has been raining ________ yesterday.

since

The correct answer is OPTION 4 -- SINCE

Here's why the other options wouldn't fit:

• for: This preposition is typically used to indicate a duration of time, but the sentence refers to a specific point in the past (yesterday).
• to: This preposition can be used to indicate direction or movement, which wouldn't make sense in this context.
• into: This preposition refers to movement to the inside of something, which again doesn't match the context of rain happening at a location.

"Since" perfectly conveys the meaning of continuous rain starting at a specific moment in the past (yesterday) and continuing up to the present time. It indicates the time frame from which the rain has been occurring.