1. The problem is to identify which expression is represented by Xavier's area model. 2. The model is a rectangle divided into 7 columns and 3 rows, representing the whole area as 1 unit by 1 unit. 3. The shaded area covers 5 columns out of 7 and 1 row out of 3. 4. The fraction of the width shaded is $\frac{5}{7}$ and the fraction of the height shaded is $\frac{1}{3}$. 5. The area of the shaded region represents the product of these two fractions: $$\frac{5}{7} \times \frac{1}{3}$$ 6. This matches the expression $\frac{5}{7} \times \frac{1}{3}$. 7. Therefore, the expression represented by Xavier's model is $\frac{5}{7} \times \frac{1}{3}$. Final answer: $\frac{5}{7} \times \frac{1}{3}$