The National Labor Relations Board has found that respondent violated section 8(a) (3) and (1) of the National 61 Stat. 140, as amended, 73 Stat. 525 (1959), 29 U.S.C. § 158(a) (3), (1) (1964), by discharging Floyd Manley Mergel because of union activities. It seeks enforcement of its order. Respondent here attacks the credibility determinations of the Trial Examiner and his choice of inferences. It persuasively argues that the discharge of Mergel was for legitimate business purposes and pursuant to legitimate managerial decisions.

On review the sole question is whether the Board’s findings are sup *481 ported by substantial evidence on the whole record. We conclude that they are and that the order is entitled to enforcement.

It is so ordered.