What "Marker" Did Rogers Use to Identify Appropriate Times to Share

What "marker" did Rogers use to identify appropriate times to share his own feelings in therapy (congruence) ?

A) when the client expressed a desire to terminate the counseling relationship
B) when it would help him refocus on his role as a therapist
C) the beginning of the second session with a client
D) the recognition of any persistent problematic reaction or feeling elicited by the client
E) Rogers espoused that it is never therapeutically advantageous to share personal feelings with a client.