One of the statements below contains a word used incorrectly. Choose the option which has the incorrect or inappropriate usage of the word.

The word "raise" is used in multiple senses across the statements. Generally, "raise" means to lift up, bring up, or build. 

We now examine each of the options individually to analyse whether the words have been used properly in the correct context.

A. The attackers decided to raise the castle to the ground.
Here, "raise" is incorrectly used. The intended meaning is to completely destroy the castle, for which the correct word should be "raze."

B. They raised their children to be freethinking boys and girls.
The word "raised" is correctly used here — it means to bring up or nurture.

C. To raise a toast to a newly-wed couple is a common practice.
This is a correct usage. Here, "raise" means to lift one’s glass in honour of someone.

D. The rays of the sun rose above the mountain.
Here, "rose" is the correct past tense of the verb "rise," and it's correctly used. There’s no confusion with "raise" here.

Option A is the correct answer in this case, as it misuses the word "raise" where "raze" is appropriate.