‘Shall be telling this with a sigh
Somewhere ages and ages hence:
Two roads diverged in a wood, and I –
I took the one less travelled by,
And that has made all the difference.’

a. What does the word ‘Sigh’ mean?

The word sigh in this text has two meanings.

One is literal: long deep breathing that can be heard.

and one that is figurative: a moment of reflection before acting.

Explanation:

The reasons behind this answer are: that in the first place we are talking about a poem and they use stylistic devices that allow the writer to transmit an indirect message hidden in words used as tools to hide it. The literal meaning of sigh well its the concept to represent a long deep breath that can be heard. Now, the second reason is that figurative language can be used to provide another level of understanding that allows the imagination of the reader to make what the writer expects. To imagine an extraordinary idea about a common action.

martians or other types of aliens represent a unique fear as opposed to zombies. vampires and other types of monsters.   in most sci-fi stories, aliens come from other worlds and have different or more advanced technology.   abductions and experimentation on human bodies that involve these technologies, or the use of these technologies against human beings and the use of unknown "powers", are a type of fear that's different from that of other types of monsters.  

the answer is:

magna carta