Select the relational algebra expression that is equivalent to the following SQL statement.

SELECT name FROM Student S$,$ Result R WHERE

S$.$no $=$

R$.$no AND grade$=\text{'}$A$\text{'}$

a$.$ Student Result $\{$:$)$

b$.$ Student $\text{'}$ Result $\{$:$)$

c$.\text{'}$ Student $$ Result $\{$:$)$

d$.,{}_{\text{n}\text{a}\text{m}\text{e}}(Sprop({}_{\text{g}\text{r}\text{a}\text{d}\text{e}}={?}^{\text{'}}A(R)))$