Sure! Let's go through each set of words to identify the one with a different sound in the underlined part:

1. **A. meet** - /miːt/
**B. Pretty** - /ˈprɪti/
**C. Seen** - /siːn/
**D. sheep** - /ʃiːp/

Different sound: **B. Pretty** (the “e” sound is different)

2. **A. peel** - /piːl/
**B. Cheap** - /tʃiːp/
**C. seat** - /siːt/
**D. behave** - /bɪˈheɪv/

Different sound: **D. behave** (the “e” sound is different)

3. **A. meat** - /miːt/
**B. begin** - /bɪˈɡɪn/
**C. picture** - /ˈpɪktʃər/
**D. miss** - /mɪs/

Different sound: **A. meat** (the “ea” sound is different)

4. **A. lick** - /lɪk/
**B. leek** - /liːk/
**C. decide** - /dɪˈsaɪd/
**D. cheek** - /tʃiːk/

Different sound: **C. decide** (the “e” sound is different)

5. **A. lick** - /lɪk/
**B. cheap** - /tʃiːp/
**C. chick** - /tʃɪk/
**D. pill** - /pɪl/

Different sound: **A. lick** (the “l” sound is different)

### Summary of different sounds:
1. Pretty
2. Behave
3. Meat
4. Decide
5. Lick

Let me know if you need more help!