<h2>Right answer: dice
</h2>
This is a sentence written in present tense (indicative) with the <u>3rd person in singular</u> he (él), which is Juan Carlos. Hence, the verb decir is conjugated as él dice (he says).
Then the complete sentence is:
<h2>Juan Carlos <u>dice</u> que va a llover.
</h2>
Juan Carlos <u>says</u> it is going to rain.
The other options are <u>incorrect</u> because:
Oye (he hears) and oyen (they hear) does not match with the context of the sentence
dicen (they say) is conjugated with the <u>3rd person in plural </u>ellos (they) and is not in accordance with the subject of the sentence.
