4. how did an overdependence on mercenary soldiers lead to the gradual decline of

the western roman empire?

a. mercenaries were not given roman armor and weaponry.

b. mercenaries were more expensive than regular soldiers.

c. mercenaries were not trained in roman military tactics.

d. mercenaries had little loyalty to the roman empire.

D

Explanation:

Edward Gibbons paints a vivid picture of that preceding scenario. He affirms:  "Roman citizens and subjects had purchased their exemption to defend their country", leaving that duty to Barbarian mercenaries. Furthermore, foreign soldiers who conquered military victories and wealth were gloriously seen in Rome.

Little by little,  the famous "Legio" (legion) began its collapse with more and more Barbarian mercenaries as recruits. These "new" soldiers have little or no loyalty to Rome but their ambitions. Turning their backs and sacking Rome.

i think it's a)sparta