Concept:Sujudus-sahwi refers to the two prostrations of forgetfulness offered during or after prayer to make up for mistakes.
Explanation:During salah, a worshipper may forget a rakah, miss a wajib act, or feel uncertain about the number of rakah completed.
Sujudus-sahwi is performed to make up for such errors or omissions.
It is not done to increase or decrease the number of rakah in any prayer.
It also does not serve to add extra quality to a valid prayer.
Therefore, it specifically corrects an error that happened during the course of salat.
The Prophet (peace be upon him) instructed Muslims to perform sujudus-sahwi whenever they forget something in prayer.
This practice keeps the prayer complete and valid.
Answer:B. correct an error in the course of salat.