Let's analyze the words based on their pronunciation.

1. **Exhibition** (ex-hi-bi-tion) - the underlined part "hi" is pronounced /hɪ/.
2. **Page** (pāge) - the underlined part "a" is pronounced /eɪ/.
3. **Loughed** (laughed) - the underlined part "augh" is pronounced /æf/.
4. **Display** (dis-play) - the underlined part "play" is pronounced /pleɪ/.
5. **Mothers** (moth-ers) - the underlined part "oth" is pronounced /ʌ/.

Now looking at the words in the context provided, we need to find the one that has a different vowel sound compared to the rest.

The answer is:

**A. Exhibition** - the "hi" is pronounced differently from the others, which generally have the long vowel sound /eɪ/ or the short vowel sounds.

Thus, the word with the underlined part pronounced differently is "exhibition."