Constance has brought an assortment of shoes to the laboratory to see which ones maximize her comfort and control of the pedals of a stick-shift car. She begins by working each of the pedals in a pair of flat T-strap sandals, followed by a pair of mid-heeled thong sandals, a pair of low-heeled T-strap sandals, a pair of high-heeled pumps, a pair of mid-heeled toe-loop sandals, a pair of flat thong sandals, and finally, barefoot. Which will let her toes flex the most?