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.
One example is below.
Q: Rope and its Usage
A: Rope
Rationale: The word 'Rope' is the key subject here, while Usage is a property of Rope.
Q: It is impervious to saIt water, and so it is very suitable for slings, falls, berthing hawsers and tow- ropes.
A:
It