1. An assumption is a missing premise: one on which the validity of the conclusion depends. Thus, option C will not be the correct answer if does not validate the conclusion of the passage.

2. The conclusion here is that Sviatovin must have been written between 1165 and 1167. The main premises supplied in support of this conclusion are that the events in the life of Prince Sviatov that the text describes occurred in 1165 and, above all, that in the diagram of Sviatov's family that accompanies the text, his father, who died in 1167, is identified as still living.

3. Thus, according to the passage, Sviatovin was written in the space of two years (1165-1167): the years that correspond to the events that occurred (1165), and the death of the father (1167). In other words, the text was composed in or after 1165, but no later than 1167, when the father died. Why? Because the father is in the diagram of the family that accompanies the text.

4. The passage establishes the date of the death of the father as a FACT. It is therefore not in question. But this fact does not establish the accuracy of the diagram. Nor does it establish the date of the composition of the text. The argument bases its conclusion on something that is actually quite flimsy. If the diagram is found to be inaccurate, the conclusion that depends on what the diagram portrays will therefore not follow. For example, how do we know that the diagram that includes the father in the family was not made AFTER the father's death? This would leave open the possibility that the text itself was written after his death.

5. The argument therefore depends on our taking for granted that the diagram does indeed represent the composition of the family AT THE TIME THAT SVIATOVIN WAS WRITTEN, as option C says - in other words, that the father was ALIVE WHEN HE WAS PORTRAYED in the diagram. Only in this case is the conclusion of the argument validated. Option C is therefore correct.

6. Concerning your hypothetical option F: this would validate the conclusion, because the text could not have been written before the occurrence of the events it describes, and likewise it could not have been written by the father after the father's death. If the father wrote the text, it must therefore have been written between 1165 and 1167.

If you like this post, please click on the THANK icon.

Try our online GMAT prep