Final answer:
The most suitable answer would be option (b) - No, I wasn't surprised because Jack had shown kindness before.
Step-by-step explanation:
In the given excerpt, it is not explicitly mentioned whether the speaker was surprised or not when they found out that it was Jack talking about August in the mummy costume. However, based on the options provided, the most suitable answer would be (b) No, I wasn't surprised because Jack had shown kindness before. This indicates that the speaker expected Jack to display empathy towards August rather than making fun of him.