The answer is the first option.
"They perform well only at very low temperatures."
Despite of advantages of Superconductors such as power and cost efficiency, these conductors have drawbacks. Semiconductors have restricted operation range of operating temperatures. They are required to work at very low temperatures.
I think the answer here is neurons, the nerve cells
Cells become haploid in cytokinesis of meiosis one because the chromosomes have divided.