5. I always try _______ at school. a) my better b) my best c) best

The correct option is 'b) my best'. Translation: Я всегда стараюсь изо всех сил в школе. Explanation: The idiomatic expression 'try my best' means to make the greatest effort possible. 'My better' is not a standard expression, and 'best' alone doesn't fit the grammatical structure of the sentence.