Final answer:
The most suitable option to complete the sentence about Nelson's hobby with small appliances is 'repairing', which implies a skilled and productive engagement with the appliances. Option 2 is the final answer.
Step-by-step explanation:
The sentence completion question is asking to fill in the blank with the activity that Nelson enjoys doing with small appliances. Each of the given options implies a different degree of involvement or expertise. Messing with implies a casual or perhaps careless interaction, repairing suggests a more skilled approach, fiddling with implies tinkering without serious intent, and selling indicates a commercial engagement with the appliances.
Without additional context, the most neutral and broadly applicable term from the provided options would be repairing. This suggests that Nelson takes a knowledgeable and possibly a professional approach to his hobby with small appliances, which is a common and understandable hobby.
Therefore, the completed sentence would be: Nelson's hobby is repairing small appliances, which is the mentioned correct option in the final answer.