A manufacturer has 3 products in his portfolio- A, B, C. They are manufactured in batches, as the cost of changing from one product to another is quite high. A can be produced at a rate of 1000 units per month, B at a rate of 800 per month and C at 700 per month. Once a product is taken up for manufacturing it will be continued for at least 2 months and a product is manufactured only once (one batch) in a year. At a time only one product can be manufactured. Products have to be manufactured before their respective demand season starts. Product A demand always happens between January and May, B between April and September and C between August and January. What is the latest month for start of production of B every year if demand for next year to follow for A, B and C are forecasted as 3000, 2000 and 1500?