Final answer:
The main clause from the given lines of 'Paradise Lost' is 'To be weak is miserable,' which is a complete and independent clause expressing a complete thought.
Step-by-step explanation:
The main clause in the lines from "Paradise Lost" is 'To be weak is miserable'. The main clause from the given lines of 'Paradise Lost' is 'To be weak is miserable,' which is a complete and independent clause expressing a complete thought. This clause contains a subject and a verb and expresses a complete thought, making it independent of the other phrases surrounding it.
The main clause from the given lines of 'Paradise Lost' is 'To be weak is miserable,' which is a complete and independent clause expressing a complete thought. The option (d) 'To be weak is miserable...' is the correct answer as it stands alone as a sentence with its own meaning, regardless of the additional context provided by the other parts of the line.