$1-$Referring to the figure shown, which of the following statement is correct?

a$-{}_{\text{i}\text{n}\text{c}\text{i}\text{d}\text{e}\text{n}\text{t}}$ and ${}_{\text{r}\text{e}\text{f}\text{l}\text{e}\text{c}\text{t}\text{e}\text{r}}$ are equal

b$-i>r$

c$-i<mi\; id="EditorElement\_414299"></mi><mi\; id="EditorElement\_414301">r</mi>$

d$-sini=sinr$