Molarity is defined as the number of moles form a certain compound in one liter of solution.
So the higher the molarity the higher the number of moles in one liter of solution, and we say that the concentration is increased. The lower the molarity the lower the number of moles in one liter of solution, and we say that the concentration is decreased.
In a nutshell:
High molarity = concentrated solution
Low molarity = diluted solution
(A) concentrated
(B) dilute
(C) dilute
(D) concentrated
(E) dilute
(F) concentrated
