How did venice acquire the nearby cities of verona and padua?

a. it hired professional soldiers called mercenaries to conquer the lands.
b. the venetian army attacked the cities and gained power in only days.
c. venice paid the cities' leaders to join its land and become one state.
d. venice signed a treaty with the cities that granted it a portion of their trade profits.

Venice acquired the nearby cities of Verona and Padua using its army, which attacked the cities and gained power in only days.

When Milanese forces felt threatened by Carraras' Paduan forces; they wisely offered  Vicenza and Verona to Venice if Venice committed stopping Carraras' Paduan forces advances to the westward.    

When Venice was offered this, Venetians took advantage of the situation and using its army captured Padua in November 1404 following a brief siege. And after the chief of Carraras' family and his son were executed (Francesco and Jacopo Carrara), in a stroke Venetians eliminated completely  Carraras' forces and extended their mainland territory to include Padua, Vicenza, and Verona.

it would be a. that is the only one i could think of