フリー問題

問題文

A category column holds city names. An analyst builds the code table for those names from the whole labeled set, applies it, and only then separates a held back part. A reviewer objects. Which statement describes the correct order and its effect?

選択肢

1. Build the code table from the fitting portion, and let unseen names fall into a default code.
2. Build the code table from the fitting portion, and let unseen names fall into a reused code.
3. Build the code table from the whole labeled set, and let unseen names fall into a reused code.
4. Build the code table from the whole labeled set, and let unseen names fall into a default code.