Politican - is it context clues?

Context clues are more commonly found in nonfiction texts than in fiction, although they are sometimes found in children's literature, often with the goal of building readers' vocabulary. Words can have multiple meanings, so being able to infer the correct definition from context is a valuable reading comprehension skill.

so yes

the eye wink at the hand; yet let that be / which the eye fears, when it is done, to see.

your answer is c) experiments with water vapor showed that elements combine in specific proportions.