Question

what is the primary role of dissolved oxygen in water for aquatic life? provides all nutrients for life to support all photosynthesis allows for better water navigation to allow aquatic animals to breathe

Explanation:

• "provides all nutrients for life" is incorrect because dissolved oxygen is not a nutrient source; nutrients like carbon, nitrogen, etc., are different.
• "to support all photosynthesis" is wrong as photosynthesis produces oxygen (in plants/algae) and uses carbon dioxide, not relying on dissolved oxygen for the process.
• "allows for better water navigation" is irrelevant; dissolved oxygen has no role in navigation.
• "to allow aquatic animals to breathe" is correct because aquatic animals (like fish) use gills to extract dissolved oxygen from water for respiration (breathing) to produce energy.

Answer:

to allow aquatic animals to breathe