Which best describes how specialized producers decrease their opportunity costs?

What describes best how specialized producers decrease their opportunity costs is that when we have someone who is a specialized producer, he will have smaller opportunity costs because he is already someone who provides and caters for a very specific and niche market.

I believe the answer is: by limiting the types of goods produced

Opportunity cost refers to the choice that has to be forfeited when we choose one option. When we limit the type of goods produced, the pool of option that available for us would also be decreased. This mean that there will be less opportunity cost crated when we choose from the options.