Shawn, Spar and Spike went out to buy some sporting goods. Shawn spent $21$ dollars on $3$ basketballs and $2$ footballs. Spark spent $18$ dollars on $4$ footballs and $1$ volleyball. Spike spent $21$ dollars on $3$ footballs and $2$ volleyballs. How much is one basketball? 
选项为:A:$$2$$$  B:$$3$$$  C:$$4$$$  D:$$5$$$  E:$$6$$$  请回答其中一个选项.