Quiz – Siman 214

In which of the following days of mourning begins unique laws, reflecting its beginning of a new intensity of mourning (barring any application of "miktzas hayom k'kulo")?

If a mourner cannot have a minyan in his home, should he daven with a minyan in shul or alone at home?

May a mourner leave his house to do a bris milah on his first day of mourning?