For the given objective function which of the following combinations of constraints would produce multiple optimal solutions?

Max Z $=10$x$1+6$x$2$

Group of answer choices

x$1+$ x$2>=15$ and x$1-$ x$2<=10$

$3$x$1+5$x$2<=30$ and x$1<=1$ and x$2<=2$

x$1<=10$ and x$2<=20$

$5$x$1+3$x$2<=15$ and x$1+$ x$2<=10$

None of the above.