what could be the problem?

Refer to the exhibit.

An administrator cannot connect from R1 to R2. To troubleshoot this problem, the administrator
has entered the command shown in the exhibit. Based on the output shown, what could be the
problem?

A.
The serial interface is configured for half duplex.

B.
The serial interface does not have a cable attached.

C.
The serial interface has the wrong type of cable attached.

D.
The serial interface is configured for the wrong frame size.

E.
The serial interface has a full buffer.

Explanation:
since the output is not forthcoming it shows that the type of cable attached is wrong,
though the cable is connected since it shows the cable type.
According to the figure DTE cable should connect to R1 on interface but while examining using
show controllers serial 0/0 command it showing that a DCE is connected so the wrong type of
cable is being used.