Issue was reported in https://h5p.org/node/113857
Steps to recreate the issue:
1. Create a Single Choice set (Stand alone or embeded in Column, Question Set and Course Presentation)
2. Uncheck "Enable Sound Effects"
3. Answer some questions wrong
4. Click on Show Solution button - Nothing happens.
Contents created in H5P.org
OS: macOS Sierra (V10.12.3)
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Safari Version 10.0.3 (12602.4.8)
Disabling the sound effects should not affect the show solution option.