Which of the following is a solution if the TD is too difficult to open?

When a terminal device (TD) is too difficult to open, checking for sharp angles on cabling is a prudent solution. Sharp angles can create excessive friction when the cables are pulled, leading to a noticeably increased resistance when attempting to operate the TD. This friction can impede the smooth movement of the device and make it challenging to open. By ensuring that the cabling is free from sharp bends or angles, one can enhance the efficiency of the device's operation, providing the user with a more manageable experience.

The other options might seem viable for easing the operation of the terminal device, but they can have drawbacks. Reducing the weight of the TD could alter its functionality or compromise structural integrity. Adding more rubber bands may provide additional tension, which could create even more resistance rather than alleviating the problem. Increasing the cable length could introduce additional slack, potentially further complicating the operation rather than addressing the core issue with friction and resistance caused by the physical configuration of the cables. Thus, maintaining proper cable alignment is critical to ensuring the TD functions as intended.