Select the word in this excerpt that means "an amount leftover" or "an excess."

"At Wanda's suggestion, Samara asked a representative from a nearby _horticultural_ society to come and advise the group on the design of the park, the best _native_ shrubs the plant, and where to put them. Samara also asked local businesses to _sponsor_ the park by the square foot so that the community would be able to afford equipment and plants. Surprised by the response, Samara went to the bank to open an account where the _surplus_ would be saved for next spring"

word choices - Horticultural, Native, Sponsor, Surplus