What were the "Proximity Talks" the Obama administration engaged in when confronting the Israeli-Palestinian conflict?

a. George Mitchell, the U.S. Middle East Envoy, would meet each side separately and seek to improve the atmosphere for negotiations to eventually lead to direct talks.
b. The repudiation of the U.S. acknowledgment of the land seized by Israel during the Six-Day War.
c. The negotiation of building homes and schools on the Gaza Strip as a step toward peaceful resettlement of the area.
d. The talks held with leaders of "Arab Spring" states, with the stated goal that peace in the region would encourage peace between the Israelis and Palestinians.
e. The summit held between President Obama and Israeli Prime Minister Benjamin Netanyahu regarding the efforts of Iran to develop nuclear weapons.

A