Worms don't have organs so im going with D
        
             
        
        
        
1st step: Transcription
DNA is unraveled and used as a template to form complimentary mRNA
mRNA then leaves nucleus in order to attach to ribosome and start 2nd step.
2nd step: Translation
tRNA with aminoacids attached will try to join mRNA\ribosome complex if tRNA triple codon matches the mRNA code it will attach aminoacid to start forming protein. This process continues until mRNA reaches STOP code, resulting in a long chain of aminoacids.
3rd step: Protein folding and modification
Usually performed by chaperonins and eventually golgi complex. Chaperonins assist in proper protein folding, while golgi apparatus performs final modifications. 
 
        
             
        
        
        
Here is the full statement: A scientist begin working by trying to explain a natural occurrence that is OBSERVABLE.
Scientific method refers to the techniques that scientists used to carry out scientific investigations and it is made up of series of steps. The first step is observation. A scientist normally begin the process of scientific investigation by observing a phenomenon that occur naturally. The observation will lead to questions, which need to be answered and which eventually lead to conduction of experiments.