A number of students from Fibonacci Middle School are taking part in a community service project. The ratio of $8^{\text {th }}$-graders to $6^{\text {th }}$-graders is $5: 3$, and the the ratio of $8^{\text {th }}$-graders to $7^{\text {th }}$ graders is $8: 5$. What is the smallest number of students that could be participating in the project? (2013 AMC 8, Question 16) 
选项为:A:$$16$$  B:$$40$$  C:$$55$$  D:$$79$$  E:$$89$$  请回答其中一个选项.