The correct answer is: A. Subject directories
Subject directories are a type of search engine that organizes websites into categories. This makes it easy to find websites that have been handpicked and recommended by someone else. Subject directories are often created by experts in a particular field, so you can be sure that the websites they recommend are high quality.
Search engines, on the other hand, do not organize websites into categories. Instead, they search the entire web for websites that match your search terms. This can be helpful if you are looking for a specific website, but it can be difficult to find websites that have been handpicked and recommended by someone else.
Meta-search engines are search engines that search other search engines. This can be helpful if you want to find a wide variety of websites on a particular topic. However, meta-search engines do not organize websites into categories, so it can be difficult to find websites that have been handpicked and recommended by someone else.
Discussion groups are online forums where people can discuss a variety of topics. This can be a helpful way to find websites that have been recommended by other people. However, it can be difficult to find websites that have been handpicked and recommended by experts.
In conclusion, subject directories are the best search tool for finding websites that have been handpicked and recommended by someone else.