What Is the First and Most Important Question to Ask

What is the first and most important question to ask when evaluating product-market opportunities?

A) "How does it fit with our objectives and resources?"
B) "What is the sales forecast for this product?"
C) "How much profit will we make this year?"
D) "How much do we need to invest in this product?"
E) "How far along is our research and development effort in this area?"