Concept:Express all terms with the same power of 10 before performing addition and subtraction.Explanation:Rewrite each term so the power of 10 is 10−4.16.54×10−5=1.654×10−46.76×10−8=0.000676×10−40.23×10−6=2.3×10−7=0.0023×10−4Now combine the coefficients:(1.654−0.000676+0.0023)×10−4=1.655624×10−4Round to two decimal places:1.655624×10−4≈1.66×10−4Answer:1.66×10−4Option A.