The correct possible sequence in the life cycle of a massive star is:
**nebula, protostar, star, super red giant, supernova, neutron star (or black hole)**
This sequence represents the formation and evolution of a massive star:
1. **Nebula** - A cloud of gas and dust where stars are born.
2. **Protostar** - The stage where the cloud collapses under gravity and begins to form a star.
3. **Star** - The main sequence phase where hydrogen is fused into helium.
4. **Super Red Giant** - The phase where the star expands and cools after hydrogen burning.
5. **Supernova** - The explosive end of a massive star's life cycle.
6. **Neutron Star (or Black Hole)** - The remnant left after a supernova, depending on the mass of the original star.
Thus, the closest match to this sequence is:
**nebula, protostar, star, super red giant, supernova, neutron star.**