符号HRC表示金属材料的（  ）指标。

A、<span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 14px">布氏硬度&nbsp;&nbsp;&nbsp; </span>

B、<span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 14px">维氏硬度&nbsp;&nbsp;&nbsp; </span>

C、<span style="FONT-FAMILY: 宋体; COLOR: black; FONT-SIZE: 14px; TEXT-DECORATION: none">洛氏硬质</span>

D、<span style="LINE-HEIGHT: 150%; FONT-FAMILY: 宋体; COLOR: black">疲劳强度</span>