A: he has made observations about the natural world b. justin notices a particular type of caterpillar feeds only on cottonwood trees in his neighborhood. in which way has justin increased his scientific knowledge? he has used technology. c he has performed a practical experiment. d he has performed an unethical experiment.

The correct answer of the given question above would be option B. The way which Justin increased his scientific knowledge is when he notices a particular type of caterpillar feeds only on cottonwood trees in his neighborhood. Scientific knowledge is the knowledge acquired with the use of the scientific method particularly observation and experimentation. 

Ibelieve your answer would be answer choice a