What is the positivity of electric circuits?

Why are some galaxies’ spectra blueshifted rather than redshifted? question 4 options:

Note: the following questions are unrelated to the balmer series or the martian. refer to your course notes. a sun-sized star will spend most of its lifetime as a: white dwarf b. red giant c. protostar d. main-sequence star

Need only answer if you think you know it