I would say that the example of satire among these options is d. Those two old brothers had been having a pretty hot argument a couple of days before, and had ended by agreeing to decide it by a bet, which is the English way of settling everything. Twain is criticizing and mocking the English for settling everything in such a trivial manner as betting.
Answer: d. Those two old brothers had been having a pretty hot argument a couple of days before, and had ended by agreeing to decide it by a bet, which is the English way of settling everything.
Explanation: A satire is the use of irony, humor or exaggeration in order to make a critique about something fool or bad of an individual or a society. In the given excerpt from Mark Twain's "The £1,000,000 Bank-Note" we can see an example of satire, when the speakers says that the brothers had had a fight or an argument, but they had made a bet to reach an agreement, so, in this way he criticizes this "English" way to settle everything.
Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities.