Recall what type of data in a column would be most efficient to use B$-$tree indexes.

In which of the following cases would it make the most sense to use a b$-$tree index?

a$.)$

SELECT $*$ FROM customer

WHERE customer$\_$id BETWEEN $2$ AND $5$;

b$.)$

SELECT $*$ FROM customer

WHERE email like $\text{'}\%$@hotmail.com';

c$.)$

SELECT $*$ FROM invoice

WHERE total $>5$;

d$.)$

SELECT $*$ FROM track

WHERE name LIKE $\text{'}\%$Of$\%\text{'}$