Algae like fertilizer. Fertilizer is good for algae. Fertilizer improves the genetic traits of algae. Algal growth rate increases with fertilizer concentration.
I am hesitating between 4 options to answer the following question, which option should I choose?
Question: A student plans to grow algal colonies in solutions with different concentrations of liquid fertilizer. Which is a clear and testable hypothesis to guide this investigation?
Possibilities:
- Algae like fertilizer.
- Fertilizer is good for algae.
- Fertilizer improves the genetic traits of algae.
- Algal growth rate increases with fertilizer concentration.

Algal growth rate increases with fertilizer concentration.