Let the domain for the variables x and y be all people in our IST 230 class. Define the predicate K(x,y) to mean "x knows y." Express the following sentences with quantified logical expressions.

a. There is someone in our IST 230 class who knows everybody in our IST 230 class.

b. Nobody in our IST 230 class knows anyone in our IST 230 class.

c. Nobody in our IST 230 class knows everyone in our IST 230 class.

d. There is someone in our IST 230 class whom everyone in our IST 230 class knows.

e. Someone in our IST 230 class knows someone in our IST 230 class.