Draw an E/R diagram that represents the following information and underline the primary keys. (20 pts)

A. Manufacturers have a company name, which we may assume is unique, an address, and a phone number, as well as the contact person name.

B. Products have a model number and a type (e.g., television set). Each product is made by one manufacturer, and different manufacturers may have different products with the same model number. However, you may assume that no manufacturer would have two products with the same model number.

C. Customers are identified by their unique Customer ID. They have email addresses and physical addresses. Several customers may live at the same (physical) address, but we assume that no two customers have the same email address.

D. An order has a unique order number, and a date. An order is placed by one customer. For each order, there are one or more products ordered, and there is a quantity for each product on the order.