当采用冷拉方法调直钢筋时,HPB235级钢筋的冷拉率不宜大于(),HRB335级、HRB400级和RRB400级钢筋的冷拉率不宜大于()
A.3%1%
B.4%1%
C.5%2%
D.2%1%
正确答案是B