see explanation.
explanation:
1. buoyant: happy and confident (e)
2. euphoric: in a state of great happiness (a)
3. jubilant: having a feeling of great happiness and excitement (b)
4. rapturous: feeling or expressing great joy (d)
*note that the difference in 1-4 can be shown by signal words such as "in a state of" for the term "euphoric," as "euphoric" would describe a state of euphoria.
5. untroubled: calm and tranquil (c)
6. cajole: to talk coaxingly and flatteringly (i)
7. harangue: to express oneself at considerable length (h)
8. quibble: to evade the truth of the point at issue by arguing over trifles (g)
9. whine: to complain in a childish, fretful manner and in a nasal tone (j)
10. rant: to talk bombastically (f)