这题选 B.
第一个选项 Private Property 与后文中的 Intellectual Work 不相容.Property 指的是有形或无形的资产,而不完全是 Intellectual Work.
第三个选项 Copyright 也不对.这是一项权利,而不是 work,而且 copyright 也不是 known only to a company 的.
第四个选项 Patent 也不对.理由同 Copyright.
第五个选项的 Knowledge Base 跟 Private/Public 完全没有关系.
回到 B 选项.Trade Secret 是商业秘密,显然既满足 Intellectual Work 也满足 Know only to a company.参看 Trade secret 的定义：
A trade secret is a formula,practice,process,design,instrument,pattern,or compilation of information which is not generally known or reasonably ascertainable,by which a business can obtain an economic advantage over competitors or customers.In some jurisdictions,such secrets are referred to as "confidential information" or "classified information".