Concept:Use exponent rules: am/n=(a1/n)m and a−n=an1. Convert fractional and negative exponents to simpler forms.Explanation:Compute 163/2 first. Since 161/2=4, then 163/2=(161/2)3=43=64. Next, 16−3/2=163/21=641 (using the negative exponent rule). Add the two results: 64+641=6464×64+641=644096+641=644097.Answer:644097 which matches option A.