Option A
General Gaius Marius changed the Roman army were Poor men became soldiers and were loyal to their generals instead of the Republic.
Step-by-step explanation:
Gaius Marius was the entirety of significant masters of the Roman Republic. He executed principal modifications to the Roman army which would improve the destiny of Rome and execute it the common dominant culture in the world. His modifications to the army modified the doom of Rome. Expert soldiers were more liable to be faithful to their officers than to the Roman republic.
He reconstructed the army into groups rather than maniples. This caused the army more adaptable. He also had parts that concentrated on specific kinds of fight and weaponry. The afresh founded army was more extra true to their generals than to the Senate and the personalities of Rome.