The correct order of periods in the Paleozoic Era from oldest to most recent is:
1. Cambrian
2. Ordovician
3. Silurian
4. Devonian
5. Carboniferous
6. Permian
The given options only include four of these periods. Within those given, the order remains consistent with the full sequence: Silurian, Devonian, Carboniferous, Permian.
The output (Y) of the given logic implementation is similar to the output of an/a …………. gate.