To find the word that has a different sound in the part underlined, let's analyze each set of words:

1. A. curious (cu) - /ˈkjʊəriəs/
B. update (up) - /ˈʌpdeɪt/
C. discuss (dis) - /dɪˈskʌs/
D. hungry (hun) - /ˈhʌŋɡri/
- The different sound is in "curious" (A).

2. A. coach (ch) - /koʊtʃ/
B. champion (ch) - /ˈtʃæmpiən/
C. stretch (ch) - /strɛtʃ/
D. Christmas (ch) - /ˈkrɪsməs/
- The different sound is in "Christmas" (D).

3. A. peer (ee) - /pɪər/
B. feel (ee) - /fiːl/
C. heel (ee) - /hiːl/
D. beef (ee) - /biːf/
- The different sound is in "peer" (A).

4. A. account (ou) - /əˈkaʊnt/
B. thought (ou) - /θɔːt/
C. about (ou) - /əˈbaʊt/
D. trousers (ou) - /ˈtraʊzəz/
- The different sound is in "thought" (B).

5. A. teenager (age) - /ˈtiːneɪdʒər/
B. greeting (ee) - /ˈɡriːtɪŋ/
C. manage (age) - /ˈmænɪdʒ/
D. engineer (ee) - /ˌɛnʤɪˈnɪər/
- The different sound is in "greeting" (B).

6. A. member (e) - /ˈmɛmbər/
B. decide (e) - /dɪˈsaɪd/
C. prepare (e) - /prɪˈpɛər/
D. request (e) - /rɪˈkwɛst/
- The different sound is in "member" (A).

7. A. sorrow (o) - /ˈsɒrəʊ/
B. folder (o) - /ˈfəʊldər/
C. common (o) - /ˈkɒmən/
D. open (o) - /ˈəʊpən/
- The different sound is in "common" (C).

8. A. carried (ed) - /ˈkærid/
B. mentioned (ed) - /ˈmɛnʃənd/
C. caused (ed) - /kɔːzd/
D. provided (ed) - /prəˈvaɪdɪd/
- The different sound is in "caused" (C).

9. A. annoy (oy) - /əˈnɔɪ/
B. honey (ey) - /ˈhʌni/
C. money (ey) - /ˈmʌni/
D. dozen (o) - /ˈdʌzən/
- The different sound is in "annoy" (A).

10. A. projects (s) - /ˈprɒdʒɛkts/
B. attacks (s) - /əˈtæks/
C. programs (s) - /ˈprəʊɡræmz/
D. notebooks (s) - /ˈnəʊtbʊks/
- The different sound is in "projects" (A).