1. One of the most terrible battles of the American Civil War was fought in July 1863, at Gettysburg.
P. The chief speech on that occasion was given by Edward Everett, a celebrated orator.
Q. Lincoln was asked to make a few remarks.
R. In November of that year a portion of the battlefield was dedicated as a final resting place for men of both armies who died there.
S. Everett's speech lasted 2 hours. Lincoln's for 2 minutes; it was over almost before the crowd realized that it had begun.
6. But the Gettysburg speech is now one of the world's immortal pieces of literature.

The correct answer is option -B

1st sentence - One of the most terrible battles of the American Civil War was fought in July 1863, at Gettysburg

Connector -In November of that year a portion of the battlefield was dedicated as a final resting place for men of both armies who died there.

Pronoun `that' refers to July 1863 in the introductory sentence.

Connectors from R to P

Sentence R- In November of that year a portion of the battlefield was dedicated as a final resting place for men of both armies who died there

Sentence P- The chief speech on that occasion was given by Edward Everett, a celebrated orator.

Sentence R tells about the occasion which is briefly explained in sentence P.

Connectors from P to Q

Sentence P- The chief speech on that occasion was given by Edward Everett, a celebrated orator.

Sentence Q- Lincoln was asked to make a few remarks.

Connectors from Q to S.

Sentence Q- Lincoln was asked to make a few remarks.

Sentence S-Everett's speech lasted 2 hours. Lincoln's for 2 minutes; it was over almost before the crowd realized that it had begun.

And in the last concluding sentence will come which is already given.