Which of the following is usually done first in the scientific method of investigation?
do research on a particular topic
ask a question based on an observation
construct a hypothesis to be tested
test with an experiment
i wanna say a

The correct answer is B. Ask a question based on an observation

Explanation:

The Scientific Method is a process with multiple steps that allow scientist and individuals to study a phenomenon and prove or disprove a hypothesis. This method includes first observing a phenomenon, defining it and asking questions; research on the topic if necessary; then creating a hypothesis or possible explanation; testing the hypothesis through experiments; analyze and interpret the data; publish the results and finally suing more experiments if necessary. According to this, the step that is first done in the Scientific Method is "Ask a question based on an observation" because this goes before any other steps.

an active site is a region that is present on an enzyme where the reactants or the substrate molecules we can say bind and experience a chemical reaction. the substrate is basically a reactant whose concentration is changing and that is converting into a product after binding at the active site of an enzyme