I think the answer is D pieces of gold and silver
The MAIN IDEA is the content or general message of a conversation or what the conversation is about.
Any other ideas brought about in the conversation is usually discussed in relation or in support to the main idea.
Yes it would calculate the changes in consumer surplus Than Guyen! :)
An address book is a book or a database used for storing entries called contacts. Each contact entry usually consists of a few standard fields (for example: first name, last name, company name, address, telephone number, e-mail address, fax number, mobile phone number).