Many farmers and gardeners compost their plant and animal waste. The living material naturally decays in compost bins, forming a dirt-like substance that's rich in nutrients. The next season, farmers use this substance as a natural fertilizer for
their crops.
A biology student has grown tomato plants for several years. Until now, he used an artificial fertilizer formulated for
tomato plants. This fertilizer caused his plants to grow faster and taller than they grew in unfertilized soil. The student
wants to know whether using natural compost will cause his tomato plants to grow faster and taller than his artificial
fertilizer.
Answer the following questions to plan an investigation using the steps of the scientific method and help the student find
the answer to his question.
Part A
What are the student's observations and inferences before he starts his investigation?
Part B
what’s the students scientific question?

well, that's easy; the answer's c, "it reduces contamination of the water and substrate of the estuary."

the correct answer is: b. pantala flavescens, because these organisms would have a high level of genetic variation due to sexual reproduction.  

because involves two organisms (parents) whose genetic material combines, sexual reproduction leads to genetic variation in new generations of offspring. the offspring is an unique organism, with new genome, more protected with the higher ability to adapted. this process is fundamental to evolution.

the last one: artificial selection/genetic engineering

plant breeding is modifying the genetic composition of the plant - but this isn't cloning (which is specifically introducing a gene into a genome). but you are artificially selecting for the phenotype that you want.

the second one is literally genetic engineering - the gene would have been cloned first and then inserted or genetically engineered into the new plant cell (the cotton).