As soon as a packet comes into a port $P$ of a switch, it does the following.
1. learn the source mac address $M$ from the packet and enter it into the L2-macaddr-table such that in future, if any packet comes with $M$ as MAC-address in destination field, it can forward to that port $P$
2. if the destination mac address is unknown to the switch, it will flood the packet onto all ports which are members of the L2-VLAN in which $P$ is also a member of. ( by default, all ports in the switch are members of a default VLAN and the packet will be flooded to all the ports if we don't change the default configs).
so in this case, packet #1 is flooded(or broadcasted as in options) packet #2 is sent out on port 1 as we have recorded the mac address from the packet #1 and the corresponding port number as said in point number 1 above.
you can refer
1. https://networkengineering.stackexchange.com/questions/13012/how-does-a-switch-learn-a-switch-table
2. https://en.wikipedia.org/wiki/Unicast_flood
why option#2 is wrong? this is because switch learns the source-MAC address from the ingress packet, not the destination-MAC as it is given in the option.
