سوال ۲ کنکور ارشد ریاضی ۱۴۰۳

This is a vocabulary/collocation sentence-completion item. The context — wearing sunscreen because of the sun — signals the idea of being subjected to the sun's rays. The word that fits both the meaning and the grammar (a passive verb followed by the preposition to) is exposed.

The fixed collocation is to be exposed to something (sunlight, danger, radiation), meaning to be left unprotected against or in contact with it:

"Be sure your child wears sunscreen whenever she's exposed to the sun."

Checking the distractors:

• demonstrated — to show or prove; does not take to the sun and makes no sense.
• confronted — to face or oppose; one is confronted with a problem, not naturally confronted to the sun.
• invulnerable — immune to harm; it would reverse the logic (if she were invulnerable, no sunscreen would be needed), and the idiom is invulnerable to, but the sentence's cause–effect (wear sunscreen → protection) requires the opposite meaning.
• exposed — correct: exposed to the sun is the standard collocation and matches the protective purpose of sunscreen.

Hence option 4.

Exam trick: Let the required preposition guide you. The blank is followed by to, and among the choices only exposed to is an idiomatic, meaning-consistent pairing.