Choose the underlined part A, B, C or D that needs correction

Here are the parts that need correction in each sentence:

1. **C**: "her to take a holiday in Japan" should be corrected to "her to take holidays in Japan" for consistency in plurality.

2. **D**: "the most interesting" should be corrected to "the more interesting" or "the most interesting" (if comparing more than two districts, use "the most"; if only comparing two, use "the more").

3. **A**: "We aren't certain who contacting" should be corrected to "We aren't certain who to contact."

4. **B**: "ran away yarn" should be corrected to "ran out of yarn."

5. **A**: "If you use the school computer lab" is correct, but check for overall clarity and grammar in the context.

Thus, the incorrect parts are A, D, A, B, and A respectively.