Maria has brought another assortment of shoes to the laboratory to see which ones maximize her comfort and control of the pedals of a stick-shift car. Maria begins by working each of the pedals in a pair of flat-heeled thong sandals, followed by a pair of closed-toe flats, a pair of flat leather flip flops, a pair of mid-heeled slide-on dress sandals, a pair of high-heeled thong dress sandals, and finally, barefoot. Which will let her toes flex the most?