In this task, you are given a sentence. You must find the primary subject in the supplied sentence. The output must be a sub-sequence in the sentence.
Example: Rope and its Usage
Example solution: Rope
Example explanation: The word 'Rope' is the key subject here, while Usage is a property of Rope.

Problem: This rope is made from the fibre of the abaca plant, which is grown extensively in the Philippine Islands and shipped from the port of Manila (whence its name), and also in Central America, Sumatra and Borneo.

Solution: This rope