单选题 Creating a relatively simple model of the known ecosystem requires a tremendous amount of work even with______set of data at our disposal; creating an accurate model for less well-understood ecosystems might well prove______pursuit.

• (A) a comprehensive … a quixotic
• (B) an expansive … a realistic
• (C) a consequential … a viable
• (D) an unproven … a feasible
• (E) an incomplete … an impossible