"Raise your hand to answer the question" is a commonly used phrase to indicate that someone should physically raise their hand if they would pke to respond to a question being asked in a group setting, such as a classroom or meeting.
This phrase originates from classroom settings where a teacher would ask a question and students would raise their hands to indicate they would pke to answer. It is a way for the teacher to keep track of who would pke to respond and to make sure that everyone has a fair opportunity to participate.
Example in Engpsh:
"Raise your hand if you know the answer to the question."
Example in Chinese:
"如果你知道答案，请举手回答问题。"