A requirement is simply a statement of what the system must do or what characteristics it needs to have. Requirements written from the perspective of user and focus on user needs are called（business requirements）. Requirements written from the developer's perspective and describe how the system will be implemented are called（system requirements）. Requirements evolve from detailed statement of business capabilities that a system should have to detailed statements of the technical way in which the capabilities will be implemented in the new system. Requirements can be either functional or nonfunctional in nature. For example, during the analysis phase of travel vehicles sales system, the system that must have the ability to search for available inventory is（a functional requirements）. The requirement that the system should be able to work on any Web browser belongs to（operational requirements）. That customer personal information is protected in compliance with the Data Protection Act is a requirement of（cultural and political）.
系统需求是对系统必须实现的功能或具备的特性的明确界定，可从不同视角与属性划分为多个核心类别。从主体视角看，业务需求立足用户端，聚焦业务目标与用户核心诉求，是系统开发的核心导向；系统需求则站在开发者视角，侧重描述系统的具体实现路径，衔接业务需求与技术落地环节。从属性维度划分，需求可分为功能性与非功能性两类：功能性需求是系统为满足业务场景必须具备的具体功能，比如库存检索、订单创建、用户信息查询等，直接对应业务操作的实际需要；非功能性需求是保障系统稳定合规运行的支撑性要求，包含多个细分方向：操作性需求关注系统的运行环境与兼容性，比如支持主流浏览器、适配多终端系统；技术需求是实现层面的技术约束，如指定编程语言、数据库类型或开发框架；安全与控制需求聚焦数据安全、访问权限管控等，防范信息泄露与非法访问；文化与政治需求涉及法律法规、行业合规及地区政策要求，比如遵守数据保护法、符合跨境业务的地区政策规范，此外还涵盖性能需求（如系统响应速度、并发处理能力）、系统约束等子类。这些需求分类相互补充，构成完整的需求体系，为系统从需求分析到开发落地的全流程提供清晰指引。
本题考察的是需求的分类。
语境定位：原句为 “Requirements written from the perspective of user and focus on user needs are called ____ Requirements written from the developer's perspective and describe how the system will be implemented are called”。空前 focus on user needs are called；空后 Requirements written from the developer s 是判断本空的关键。
答案判断：上下文强调的专业概念是“业务需求，从用户或业务角度描述目标和需要”，该词能把前后语义自然衔接起来。因此应选 business requirements。
选项辨析：
A. operational requirements：是非功能需求的一种，指系统运行环境方面的要求，不符合题干。
B. business requirements：从用户角度出发，关注业务目标和用户需求，符合语境。
C. technical requirements：指实现方式上的技术约束，不符合题干。
D. system requirements：从开发者角度出发，不符合题干。
因此，选项 B 正确。