承重结构是由钢筋混凝土或钢材制作的梁、板、柱形成的骨架承担，墙体只起围护和分割作用，用于多层和高层建筑。( )

— Is it OK to take this seat
— Sorry,（）.

A. here you are

B. take it

C. it's taken

D. never mind