Same of the examples that we could apply the pared sample t-test are (choose all correct answers) A Observations (e.g., weight) from two independent groups (e.g. high-income and low-income groups). B Repeated measures on the same subject at two different times C Observational studies of identical twins with each member of the twin assigned to two different conditions. D An experiment (e.g., on weight change) with subjects randomly assigned to two different conditions (e.g., diet and placebo groups). E Experiments in which similar experiment units form pairs (e.g. matched-pair) F Pairing by time (e.g, lab test of mutant vs nonmutant stains on each day through different days)