Bar charts, also known as Gantt charts, are a type of graphical representation used in project management to display the schedule of activities. They are commonly used to track the progress of projects and to plan and schedule tasks. However, there are certain characteristics of bar charts that make option A, "Bar charts are preferred for very big projects," not true.

Bar charts are not limited to a specific project size. They can be used for both small and large projects, depending on the complexity and requirements of the project. The size of the project does not determine the suitability of using bar charts. Therefore, option A is incorrect.

Let's examine the other options to understand the characteristics and limitations of bar charts:

b) Only major activities are shown on bar charts:
In bar charts, both major and minor activities can be shown. Major activities are typically represented by longer bars, while minor activities are represented by shorter bars. This allows for a comprehensive representation of the project schedule, including all the necessary tasks and their durations.

c) Bar charts do not show progress of work:
This statement is incorrect. Bar charts are specifically designed to show the progress of work. The length of the bars in a bar chart represents the duration of each activity, and the progress is indicated by shading or coloring the portion of the bar that has been completed. This visual representation helps project managers and stakeholders track the progress of tasks and identify any delays or bottlenecks.

d) Bar charts do not show inter-dependencies of the activities:
This statement is also incorrect. Bar charts can effectively display the inter-dependencies of activities. By arranging the bars in a logical sequence and connecting them with arrows, the dependencies between activities can be clearly depicted. This allows project managers to understand the critical path of the project and identify any activities that are dependent on the completion of others.

In conclusion, option A is the correct answer because bar charts can be used for projects of any size, not just very big projects. The other options are incorrect because bar charts can include both major and minor activities, show the progress of work, and display inter-dependencies between activities.