—Shall I give you a ride as you live so far away?

—Thank you. ________.

A．It couldn't be better

B．Of course you can

C．If you like

D．It's up to you

图5-24所示一正方形截面的混凝土柱，浇注在混凝土基础上。基础分两层，每层厚为t。已知P=220kN，假定地基对混凝土板的反力均匀分布，混凝土的容许剪应力[τ]=1.5MPa。试计算为使基础不被剪坏，所需的厚度t值至少应为（）。

A. 111.1mm

B. 172mm

C. 105mmD. 166.7mm