Read the following passage and choose among A, B, C or D the correct answer to each of the questions.

Telecommuting is some form of computer communication between employees' homes and offices. For employees whose job involves sitting at a terminal or word processor entering data or typing reports, the location of the computer is of no consequence. If the machine can communicate over telephone lines, when the work is completed, employees can dial the office computer and transmit the material to their employers. A recent survey in USA Today estimates that there are approximately 8.7 million telecommuters. But although the numbers are rising annually, the trend does not appear to be as significant as predicted when Business Week published "The Portable Executive" as its cover story a few years ago. Why hasn't telecommuting become more popular?

Clearly, change simply takes time. But in addition, there has been active resistance on the part of many managers. These executives claim that supervising the telecommuters in a large workforce scattered across the country would be too difficult, or at least systems for managing them are not yet developed, thereby complicating the manager's responsibilities.

It is also true that employees who are given the option of telecommuting are reluctant to accept the opportunity. Most people feel that they need regular interaction with a group, and many are concerned that they will not have the same consideration for advancement if they are not more visible in the office setting. Some people feel that even when a space in their homes is set aside as a work area, they never really get away from the office.

With which of the following topics is the passage primarily concerned?