Read the following context and choose the best option to answer the question.
Context: After we finished work on the deck we drove around different places selling watermelons out of the back of Norm 's truck . We got about 150 for $ 100 and sold them 1 for $ 3 or 2 for $ 5 . We figured it 'd be an evening of easy money . Only we only sold about 20 so we did n't even make back our investment .
Question: Why did we figure it 'd be an evening of easy money ?
Options: 
- Watermelons can be used as furniture
 - None of the above choices .
 - Everyone must have a watermelon
 - Selling would be easy because the cost of the melons was only about .75 per melon and we could sell them for much more than that .


Selling would be easy because the cost of the melons was only about .75 per melon and we could sell them for much more than that .