Monotone is referred to having a one, single tone that is usually described as flat and does not either rise nor lower in pitch.
The answer would be Suspenseful.
Credits to them ↓
Can u be more specific on what u want to exactly say to them or your main idea
A seems the most logical in this sense, since parents are portrayed (and majority do) sacrifice a lot so their children can live good and better lives than they did.