The correct answer is C) two-stranded hemp cord. Marline is a type of two-stranded, tightly twisted cordage, typically made from hemp fibers. It is commonly used for seizing, whipping, and other applications where a strong, durable line is needed on ships and boats. The two-stranded construction and hemp material make marline the correct choice from the options provided. The other options are incorrect because: A) sail twine is a lightweight, single-stranded line, B) four-stranded sisal line is a different type of cordage, and D) three-stranded cotton line does not match the description of marline.