German A1 Level Question

The word 'früh' is correctly used in the context of time, meaning 'early'. Sentence c uses 'früh' to indicate that he arrived early at the party. In sentence a, 'früh' is used in the wrong context; 'early' should be used before 'to bed'. Sentence b and d misuse 'früh' entirely, as it does not apply to apples or colors.