consider a relation with the following schema: employees (eid, ename, salary, title, age) suppose that the following indexes exist: a hash index on eid, a b -tree index on salary, a hash index on age, and a clustered b -tree index on (age, salary). assume the employees relation contains 1,000,000 tuples; each attribute is 20 bytes long; the page size is 4096 bytes; the range for salary is $51k-$100k; the range for age is 21 to 70 years old. for each of the following selection conditions, compute the cost of the most selective access method for retrieving all tuples that satisfy the condition.