To obtain the measure of segment AD, add the measurement of segment AC and segment CD.
![AD=AC+CD=2(3)/(8)+1(1)/(4)](https://img.qammunity.org/2023/formulas/mathematics/college/dmx46n2dnvp7x8ot9zt51jdvn0zd35vt7n.png)
Rewrite the fraction part as similar fractions. Multiply the numerator and teh denominator of the second fraction by 2 to obtain 8 in the denominator.
![\begin{gathered} AC+CD=2(3)/(8)+1(1\cdot2)/(4\cdot2) \\ =2(3)/(8)+1(2)/(8) \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/531lg59pfb2hiquk156kzij6ojvounk3e2.png)
Add the whole numbers, 2 and 1. Add the numerators, 3 and 2, and then copy the common denominator, which is 8.
![\begin{gathered} AD=2(3)/(8)+1(2)/(8) \\ =3(5)/(8)_{} \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/college/c7z6a6emus7e3bf80dxrbaf4buvb2pgdtw.png)
Therefore, the correct answer is the third option, 3 5/8 in.