The correct answer is A. Value of volunteering
Step-by-step explanation:
An idea web is a type of graphic used with the purpose of showing the relationship between different concepts, especially the concepts or ideas that are part of a major one. Because of this most idea webs are organized by a main idea or point placed in a center circle and sub-ideas placed in circles around it. Besides this, the sub-ideas should be related in the same way to the main idea and describe or explain this main idea. In this case, the sub-ideas are "new friendships", "achievements", "satisfaction" and "improved community" that shows all of these are effects or features of some issue. Therefore, the topic that best complete this idea web is "Value of volunteering" because this is the only topic that directly connects to the sub-ideas and thus, the sub-ideas explain it as "new friendships, achievements and satisfaction" are all features, effects or values of volunteering.