Elabora un plan de emergencia pará reducir riesgos frente una amenaza natural o aantropica necesito ayuda se los agradeceré mucho♥️

Which revelation resulted from the observation of the spectrum of different galaxies? a. there were more galaxies whose spectrum was blueshifted b. there were no galaxies whose spectrum was redshifted c. there were more galaxies whose spectrum was redshifted d. there were no galaxies whose spectrum was blueshifted