Which expression yields the largest value?
0.5÷0.20.5 \div 0.20.5÷0.2
0.2÷0.50.2 \div 0.50.2÷0.5
0.5×0.50.5 \times 0.50.5×0.5
12+14\frac{1}{2} + \frac{1}{4}21+41