Golden algae are a group of protists whose color is due to carotenoid pigments: yellow and brown. Most have two flagella and all are photosynthetic. A group of students was given a sample of one of these (Dinobryon) that is colonial. Their instructions were to design two or more experiments that could be done with these organisms. The students decide that for one of their experiments, they want to see whether the organisms can photosynthesize. Which of the following is the most appropriate hypothesis for their experiment?

a. If the Dinobryon are kept in the dark, then one-half will be expected to die in 5 days.
b. If the Dinobryon can live without exposure to light for > 5 days, then they must be able to photosynthesize.
c.If the Dinobryon can live > 5 days without added food, then they must be able to photosynthesize.
d.If the Dinobryon are able to photosynthesize, then they should contain photosynthetic pigments
e. If the Dinobryon photosynthesize, then they must need no other minerals or nutrients and will be able to live in distilled water and light alone.

Golden algae are the protists which can photosynthesize and possess flagella. In the given question, a hypothesis has to be proposed which could explain the photosynthesis process in the golden algae process.

A hypothesis is a predicted statement which is based on the previous knowledge and can explain the natural event in. Also, the hypothesis can be tested with the experiments.

The hypothesis shows the possibility of the natural event therefore hypothesis begins with the If the word. In the given question, the statement that if Dinobryon can photosynthesise then they should contain the photosynthetic pigments is considered correct hypothesis which can be tested through the experiments.

Thus, Option-D is the correct answer.