Answer :
To solve the exercise it is easier if you first convert the mixed equation into improper, like this
[tex]1\frac{3}{4}=\frac{4\cdot1+3}{4}=\frac{4+3}{4}=\frac{7}{4}[/tex]Now, you just have to multiply the amount of flour that is required by the amount of recipe that Lena wants to prepare, like this
[tex]1\frac{3}{4}\cdot\frac{2}{3}=\frac{7}{4}\cdot\frac{2}{3}=\frac{7\cdot2}{4\cdot3}=\frac{14}{12}[/tex]Simplifying you have
[tex]\frac{14}{12}=\frac{2\cdot7}{2\cdot6}=\frac{7}{6}=1.16[/tex]Therefore, the amount of flour Lena will need is 1.16 cups flour, and the correct answer is D. 1.16.