请教一道语法题

际遇2011

请教各位大神一道语法题，谢谢！
The study undertaken by the Department of the Interior will involve examination and tagging of the California condor in order to obtain information about their daily movements, foraging habits, and sites where they nest.
A. their daily movements, foraging habits, and sites where they nest
B. their daily movements, foraging habits, and their nesting sites
C. its daily movements, foraging habits, and nesting sites
D. its daily movements, foraging habits, and about nesting sites
E. daily movements, foraging habits, and sites in which there are nests
答案是C。我的疑问是 “the California condor ”这种，the + 名词 不是应该指代这一类事物，谓语用复数吗？那么在划线处是不是也应该用their 来体现这一集合名词的复数意义？
拜谢大神指点！

keepfighting

the 是特指 不影响谓语的单复数
The scientists are confident about the research (这些科学家)
Scientists are confident about their research
总的还说还是看the之后的名词来判断谓语的单复数