Read the following excerpt from a US court opinion:
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enough to overcome the far more fundamental principles involving the sanctity of certification/recognition and exclusive representation. We are likewise aware of no case in which a union has been permitted to bargain over the conditions of employment of excluded supervisory personnel. The absence of any such case is easily explained. Under the FSLMRS (and the NLRA), supervisors are members of management and are legally disabled from belonging to any bargaining unit, see 5 U.S.C. § 7112(b)(1); as such, the same policies that prevent a union from purporting to regulate the conditions of employment of persons in other units apply with equal force to supervisory personnel. Indeed, the Authority itself has recognized as much. See National Council of Field Labor Locals, 3 F.L.R.A. at 292 . With regard to non-employees and employees
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What is the most suitable continuation to the opinion? Your options are:
A. holding that a constitutional violation by a subordinate is a predicate for supervisory liability under  1983
B. holding that an employer alone is liable for a violation of title vii by supervisory employees
C. holding that employer may be held liable under  1981 for discrimination by supervisory employee
D. holding nonnegotiable proposal specifying procedure for filling management and supervisory positions
E. holding that supervisory liability under  1983 requires a showing that the supervisory official at least implicitly authorized or approved or knowingly acquiesced in the unconstitutional conduct of the offending subordinate
Reply with [A, B, C, D, E] only.