Of the following, which is the best feature of using portfolios?

• A. They focus on what children have failed to learn.
• B. They're less time-consuming than giving a traditional paper/pencil test.
• C. They're more time-consuming than giving a traditional paper/pencil test.
• D. They focus on what children can do.

The best feature of using portfolios is option D. They focus on what children can do.