Which of the following sentences is correct?

• সাধারণত Phone শব্দটির পূর্বে  by বসে।
- কিন্তু 'the phone' এর পূর্বে over/on বসে।
- তাই নিয়মানুযায়ী সঠিক বাক্য হবে - The leader will inform the employees about the meeting on the phone.

• By phone: The company can be reached by phone on this number
• Over the phone: You can arrange a meeting over the phone.
• On the phone: She has spent hours on the phone in recent weeks.

Source: Cambridge Dictionary.