Explanation:

Secondary storage refers to non-volatile storage devices that retain data even when the computer is powered off.

• Examples include hard disk drives (HDDs), solid-state drives (SSDs), USB flash drives, and optical discs.
• These devices do not require a constant power supply to maintain the stored data, making them suitable for long-term data storage.

Analysis of Other Options:

• (B) does not use magnetic media: Incorrect. Many secondary storage devices, such as HDDs and magnetic tapes, use magnetic media to store data.
• (C) consists of four main types of devices: Incorrect. Secondary storage encompasses a variety of devices beyond just four types. The number and classification can vary based on context and technological advancements.
• (D) does not store information for later retrieval: Incorrect. The primary function of secondary storage is to store data persistently for later retrieval, distinguishing it from primary (volatile) memory.

Therefore, the most accurate statement is: Secondary storage does not require constant power.