Question

which aspect of algae biofuel production leads to its high cost?
reactors require energy to maintain the algae culture and provide carbon dioxide.
significant amount of land must be acquired to house ponds or reactors.
due to contamination risks, insurance premiums are costly for producers.
required fertilizers are much more expensive for algae than for crops.

Explanation:

Maintaining algae cultures in reactors demands continuous energy for temperature control, mixing, and CO₂ supply—this is a primary driver of high production costs for algae biofuel. While other options involve costs, energy for reactor operations is a well-documented major cost factor.

Answer:

A. Reactors require energy to maintain the algae culture and provide carbon dioxide.