Rule of thumb is a guide or refs principle of some sort. For example, "as a rule of thumb, I do not begin big projects until the weekend." I hope this helps.
I know it's not B, because arrogance is basically like pride or self-absorption, so that's false.
Apprehension, or C, is also false. The meaning of apprehension is basically anxiety or tension, so that is also false.
D is also not correct because donor is someone who gives something away to another person. Though donor is usually associated with giving away organs to help other people, it can be other things.
But a recipient is someone who receives something, such as a "Best Student" award!
A is the correct answer! :)
Gabriels tears are generous because until that moment he had been egoistic and distracted toward Gretta. When he became conscious of that fault, he release his generosity in a pity crying.
