With just the information provided I think you would naturally assume either
* that the call in audience is large and $40\%$ male and all are equally likely to call in. That would make the answers to c) and d) $40\%$ and $60\%$. Then the book is just plain wrong.
or
* that the audience is large and half male half female, which would explain the answer to d) but not to c).
Perhaps there is context with more about the audience or some strange definition of "experimental probability" that leads to the book's answers.
**Edit:** I contacted the publisher. That is in fact an error, known since 2016. The correct answers are $40\%$ and $60\%$.
See the list of errata here:
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