You need to design an ER diagram for a pharmacy with the specification below 0 Patients are identified by an SSN, and ther names, addresses, and ages must be recorded. O Doctors are identified by identified by an ssN. For each doctor, the name, specialty, and years of experience must be recorded o Each pharmaceutical company is identified by name and has a phone number o For each drug, the trade name and formula must be recordered. Each drug is sold by a given pharmaceutical company, and the trade name identifies a drug uniquely from among the products of that company. If a pharmaceutical company is deleted, you need not keep track of its products any longer. Each pharmacy has a name, address, and phone number. o Every patient has a primary physician. Every doctor has at least one patient. o Each pharmacy sells several drugs and has a price for each. A drug could be sold at several pharmacies, and the price could vary from one pharmacy to another