Here are the answers to the pronunciation question:

1. **1. A. cook** (the 'oo' is different: 'oo' in cook is pronounced as /ʊ/ while in the others, it's /uː/)
2. **2. A. pool** (the 'oo' in pool is pronounced as /uː/)
3. **3. A. tourist** (the 'ou' is different: pronounced /ʊə/ in 'tourist' vs. /aɪ/ in others)
4. **4. B. good** (the 'oo' is pronounced as /ʊ/, different from the others)
5. **5. A. moon** (the 'oo' is pronounced as /uː/, different from the others)
6. **6. A. activity** (the stress pattern is different than in 'hospital' and 'garden')
7. **7. A. ensure** (the 'en' is pronounced differently in 'ensure')
8. **8. B. toy** (the 'oy' sound differs from the others)
9. **9. C. keen** (the 'ee' sound is different, pronounced as /iː/)
10. **10. A. today** (the 'to' sound is pronounced differently)
11. **11. A. hold** (the vowel sound differs)
12. **12. A. dry** (the 'y' sound is different from the others)
13. **13. C. unload** (the 'un-' prefix is pronounced differently)
14. **14. C. advise** (the 'vise' part is pronounced differently)
15. **15. A. coach** (the ending 'ch' sound is pronounced differently)

In summary, the words that are pronounced differently compared to the others are:

1. A. cook
2. A. pool
3. A. tourist
4. B. good
5. A. moon
6. A. activity
7. A. ensure
8. B. toy
9. C. keen
10. A. today
11. A. hold
12. A. dry
13. C. unload
14. C. advise
15. A. coach