Choose the appropriate preposition from the list below: Nasir will dissolve the matter by discussing it ____ the phone.

সঠিক উত্তর: over 

The phrase over the phone, means that something is done using the phone as a way to do it. অর্থাৎ ফোন ব্যবহার করে বা ফোনের মাধ্যমে কোন কিছু করা।  যেমন:

- She told him the news over the phone. ( চিঠি বা অন্য কিছু দিয়ে নয়, বরং সে ফোনের মাধ্যমে তাকে নিউজটি দিয়েছে, অন্য কোন মাধ্যমে নয়। 
- We ordered take-out over the phone before driving to the restaurant to pick it up.

এছাড়াও,
 The phrase "on the phone" means that someone is using a telephone. The following examples show how "on the phone" is used। 
Please do not interrupt your mother while she is on the phone. [=while she is using the phone]

Source: The Britannica Dictionary