Question

Which of these will most likely happen if Earth's axis becomes straight up and down instead of being tilted? there would be no seasons there would be no days and nights only polar regions would experience seasons only equatorial regions would experience days and nights

Answer 1

There would be no seasons;
Different parts of the planet would never face more or less towards the sun so it would never get warmer and cooler so profoundly as from summer to winter and vice versa.