The most likely reason the data transfer failed is D. The older phone utilized different wireless protocols.
Wireless protocols are the standards that devices use to communicate with each other over a wireless network. Different wireless protocols have different features, such as speed, range, security, and compatibility. If the older phone and the new phone use different wireless protocols, they may not be able to transfer data smoothly or at all. For example, if the older phone uses Wi-Fi Direct and the new phone uses Bluetooth, they may not be able to connect or recognize each other.
To avoid this problem, you should make sure that both devices support the same wireless protocol and that they are in range of each other. You can also use a third-party app or service that can transfer data between different devices, such as Smart Switch1 or Move to iOS2. These apps can help you transfer data such as contacts, photos, messages, and more from your old phone to your new phone.
Reference:
2: Failure of data transfer from android to ... - Apple Community
1: Smart Switch Transfer Issues - Samsung Electronics America