A company has just completed its first year of operations. The following information is available:

Beginning inventory: 100 units at $10 per unit
Purchases: 500 units at $12 per unit
Ending inventory: 200 units
Sales: 300 units at $20 per unit
a) Calculate the cost of goods sold for the year using the FIFO method.
b) Calculate the cost of goods sold for the year using the LIFO method.
c) Calculate the cost of goods sold for the year using the weighted average method.
d) Which inventory valuation method (FIFO, LIFO, or weighted average) results in the highest cost of goods sold and the lowest net income? Explain your answer.