Which statement about the corona is true?

• A. It is the hottest region of the Sun.
• B. It is a dense, solid surface.
• C. It is very thin and faint, and its shape depends on the Sun's magnetic field.
• D. It blocks the solar wind.

Answer: (C)

The corona is the Sun’s outer atmosphere and is extremely tenuous, so it appears very thin and faint. Its shape isn’t a fixed solid layer; instead, the hot plasma in the corona follows the Sun’s magnetic field lines, creating features like streamers and coronal holes that change with solar activity. This magnetic-field–guided structure is why the corona looks different at different times and places.

The other statements don’t fit because the corona isn’t a dense solid surface, and the hottest part of the Sun is the core, not the outer corona. Also, the corona is not something that blocks the solar wind; the solar wind streams outward from the corona along magnetic field lines.