Answer:
The blue jay is a beautiful winter bird.
Step-by-step explanation:
Opinions are the judgement of a person/idea/topic from the speaker. It's not necessary based on facts and evidence. Opinions cannot be backed up by evidence to determine if it's true.
D is judging a blue jay, so it is an opinion.
A, B, and C can be proven by evidence that they are true. So they are not opinions.