--Shall we discuss the problem at the meeting today?

---We’d better not.  ,the problem isn’t so burning. What’s more, the manager won’t be back until tomorrow.

A．Begun with

B．Beginning with

C．To begin with

D．Being begin with

绿茶干茶的绿色是由（）决定的，茶汤中的绿色是由水溶性色素决定。