Concept:Solve the first-order differential equation by substitution, then use the initial condition to find the constant.Explanation:Let z=y+5.Then dxdz=dxdy.The differential equation becomes dxdz=z.Its solution is z=Cex.Since z=y+5, we get y+5=Cex.Using y(0)=4: 4+5=Ce0, so C=9.Therefore, y=9ex−5.Now substitute x=log2.Since elog2=2, we have y(log2)=9(2)−5=18−5=13.Answer:y(log2)=13Option D.