A subordinating conjunction enables to give transition to the ideas of the sentence and it also enables to join a main clause to a subordinate clause. In the sentence above, the subordinating conjunction used in the sentence is Whether.
Always remember that the subordinating conjunction will be followed by a clause.
Science fiction takes place in the near future to far future, while historical fiction takes place in history.
Gloat in the sentence means to brag. Basically, the third selection. "To make fun of someone."
Hopefully this helps :)
