a)
oh; double; double; oh; oh
b)
0766 I 311 I 4020
c)
- oh seven double nine six | oh seven two | five three one
- oh eight three double five | eight four two | seven oh six
- eight one oh one three | double oh five | four nine two
- double four seven eight | oh five one | three four nine
d)
- Sam → nine two four oh | four seven three
- Ahmed → five eight two three | oh three one
- Nina → seven double eight six | three oh one
- Chen → three double six two | one four nine
- Simon → oh four six double three | seven three | double nine one two
- Fatima → oh eight seven oh one | six four two | five one three
- Yuko → double oh double four two | eight one six | nine double three
- Penny → double oh two eight five | nine double five | four two seven