Gets or sets the trust anchors: a signer's certificate chain is trusted when it reaches one of them, whether a root or an intermediate. Empty by default, so no chain is trusted until anchors are given.
public IReadOnlyList<X509Certificate2> TrustAnchors { get; set; }
RFC 5280 §6.1.1 (d): an anchor's own validity and constraints are not checked; it is trusted as given.