What type of connectivity detail indicates no successful data transfer?

The choice indicating "Refused" is the correct answer because it specifically denotes that a connection attempt was actively rejected by the target system or service. This rejection implies that no successful data transfer could occur, as the request to establish a connection was denied.

In contrast, "Accepted" signifies that a connection request was received and acknowledged by the target, potentially allowing for data transfer. "Timeout" indicates that the connection attempt took too long and was abandoned, which again implies that no successful transfer occurred, but it does not directly state that the connection was actively refused. "Established" refers to a successful connection where data transfer can take place, making it the opposite of what is being asked in the question. Thus, understanding these distinctions clarifies why "Refused" is the most accurate representation of a scenario where no successful data transfer has taken place.