An article about half-lives describes a parent isotope. what is a parent isotope?

the isotope that forms from the radioactive decay of a less stable isotope

the isotope that forms from the radioactive decay of a more stable isotope

an isotope that undergoes radioactive decay to form a less stable isotope

an isotope that undergoes radioactive decay to form a more stable isotope

C=59(f−32)the equation above shows how temperature f, measured in degrees fahrenheit, relates to a temperature c, measured in degrees celsius. based on the equation, which of the following must be true? a temperature increase of 1 degree fahrenheit is equivalent to a temperature increase of 59 degree celsius. a temperature increase of 1 degree celsius is equivalent to a temperature increase of 1.8 degrees fahrenheit. a temperature increase of 59 degree fahrenheit is equivalent to a temperature increase of 1 degree celsius. a) i onlyb) ii onlyc) iii onlyd) i and ii only