What figurative language is:

The abandoned schoolhouse sadly remembered the happy laughter of children

The answer is Personification.

Explanation:

Personification is used to give human qualities to non-living things. For example: The sun smiled at us. Smile is a human quality given to a non-living thing like the sun.

In the example above, the words sadly and remembered makes this a Personification.

The schoolhouse in this case is a non-living thing. Yet, it is described as feeling sadness and remembering the school children.

Sadness and remembering are human qualities that were given to the non-living abandoned schoolhouse.

Hence, "The abandoned schoolhouse sadly remembered the happy laughter of children" is an example of personification.