With no explanation, chose the best option from "A", "B", "C" or "D". of action, and res judicata will not apply to bar the present suit. Unfortunately for Mr. Dwyer, however, many of those same claims are precluded by the valid settlement agreement which he executed with the City and by the doctrine of collateral estoppel. Thus, the first three questions submitted by plaintiffs as issues they could not raise in the mandamus action {see p. 269, supra) may not be raised in this section 1983 case. Question 4, concerning newly named individual defendants, states a claim that may be pursued in the instant action. However, by virtue of the valid settlement agreement, the issue may not be used as a vehicle to assert liability against the City. See Monell v. New York City Dept. of Social Services, 436 U.S. 658, 691, 98 S.Ct. 2018, 2036, 56 L.Ed.2d 611 (1978) (<HOLDING>). The remaining questions are not precluded

A: holding that county liability under  1983 cannot rest on a theory of respondeat superior
B: holding that a municipality may be held liable as a person under  1983
C: holding inter alia that a municipality cannot be held liable under section 1983 on a respondeat superior theory
D: holding that a party can be held liable for securities fraud on an agency or a respondeat superior theory
C.