Obvious:Clear::Obtuse:

Dull

The word that best completes the analogy Obvious:Clear::Obtuse: is Dull.

• Obvious means easily seen or understood.
• Clear means easy to understand or see through.
• Dull means not sharp or bright.
• Acute means sharp or keen.
• Clever means having or showing quick and sharp intelligence or wit.
• Request means a formal or informal asking for something.