C is quite a straightforward choice.
A is wrong because the passage doesn't mention that the equipment contributes to the taste/quality of blended coffee.
B is straightforward - if competitors dont use the best coffee beans in the blend, they're not as good anyway.
C is true because despite buying the most amount of best coffees, if it sells by far maximum coffee, the proportion of columbian coffee in the blend decreases.
D is irrelevant - to the quality and focusses on cost.
E, if true, could merit attention. However, it contradicts the first statement "The worldâ€™s best coffee beans come from Colombia. The more Colombian beans in a blend of coffee, the better the blend".
Any other choices?
Who says elephants can't dance?