Read and complete the sentence with the correct part.

One day, a group of young people came to me and said they had something to say. I was very surprised. They said they were all grateful for the changes I brought into their lives through peer education. I was so happy to hear this that it aroused joy in my heart. This experience made me understand that only volunteer work can have such a profound impact on people’s lives.

The word profound in “volunteer work can have such a profound impact …” means …

• significant.
• instant.
• severe.
• visual.