The graph of g(x) ​​is the graph of f(x)=5x+15 compressed horizontally by a factor of ​ 1/5 ​ .

Which equation describes the function g?

A. g(x)=25x+75 ​

B. g(x)=x+15 ​ ​

C. g(x)=x+3

​D. g(x)=25x+15 ​