Here are the words that have the underlined parts pronounced differently and the corresponding syllable stress:

### I. Pronunciation:
1. **A. single** (the 's' is pronounced as /s/)
Others: music, platinum, contest, debut, album, etc. (the 's' is pronounced differently or has a second syllable)

### II. Stress:
1. **A. become** (stressed on the second syllable)
Others: idol, release, artist, etc. (stressed on the first syllable)

### Explanation:
- In the first section (I), “single” has a different sound for the 's' compared to the other choices, which include different sounds or syllables.
- In the second section (II), "become" has the stress pattern that differs from the others, as the stress lies on the second syllable in contrast to the first syllable in the other words.

Let me know if you need further clarification!