ERSPAN encapsulates the mirrored packets with a new IP header that has the source IP address specified in the 'origin ip address' command. The encapsulated packet is then sent out of the router using the routing table. However, the ACL on the source interface Gi0/0/0 is applied to the original traffic entering the interface, not to the encapsulated packets.
The encapsulated packets are generated by the router and are not subject to the ACL on the source interface. The ACL would affect the original traffic being mirrored, but the symptom is that the collector receives no packets. The correct root cause is that the ACL is blocking the original traffic, so there is nothing to mirror.
But the scenario says the collector receives no packets, meaning the mirrored packets are not being sent. The more likely issue is that the ACL is applied to the outgoing direction on the interface that sends the encapsulated packets, but the scenario says the ACL is applied to Gi0/0/0, which is the source interface. The encapsulated packets are sent out of a different interface (the one that has the route to the collector).
The ACL on Gi0/0/0 does not affect the encapsulated packets. However, if the router uses the same interface to send the encapsulated packets, the ACL might block them. The correct answer is that the ACL is applied to the source interface and may block the encapsulated packets if they are sent out that interface.