Which improper fraction is not equivalent to $3\frac{1}{2}$?

Radha has $4$ routes that she can take to go from home to school. 

Route A$=4\frac{1}{4} \mathrm{km}$

Route B$=1\frac{1}{2} \mathrm{km}$

Route $C=1\frac{3}{8} \mathrm{km}$

Route D$=1\frac{1}{8} \mathrm{km}$

Arrange the routes in ascending order.

Naina bought a plant that was $4\frac{2}{3} \mathrm{cm}$ tall. IN the first week, it grew $1\frac{7}{8} \mathrm{cm}$ and next week it grew $3\frac{1}{2} \mathrm{cm}$. Now, how tall is Nainas plant$?$