question: Most mammals are viviparous, which refers to what reproductive result?
distractor3: laying eggs
distractor1: identical twins
distractor2: spawning
correct_answer: live birth
support: Most mammals are viviparous. Their young are born live. They are born either as relatively large, well-developed fetuses or as tiny, immature embryos. Mammals that are viviparous are called therian mammals . Only a few mammals lay eggs instead of giving birth to an infant or embryo.