英语翻译

英语翻译
He then set up experiments with caged starlings and found that their orientation was,in fact,in the proper migratory direction except when the sky was overcast,at which times there was no clear direction to their restless movements.
3.Which of the sentences below best expresses the essential information in the highlighted sentence in the passage?Incorrect choices change the meaning in important ways or leave out essential information.
○ Experiments revealed that caged starlings displayed a lack of directional sense and restless movements.
○ Experiments revealed that caged starlings were unable to orient themselves in the direction of their normal migratory route.
○ Experiments revealed that the restless movement of caged starlings had no clear direction.
○ Experiments revealed that caged starlings' orientation was accurate unless the weather was overcast.
为何选D,
我懂了选D,但是原句子还希望翻译一下!