A stone is dropped from a height ℎ. Simultaneously, another stone is thrown up from the ground which reaches a height 4 ℎ. The two stones cross other after time

Question : A stone is dropped from a height ℎ. Simultaneously, another stone is thrown up from the ground which reaches a height 4 ℎ. The two stones cross other after time

(A) $\sqrt{\dfrac{h}{8g}}$

(B) $\sqrt{8gh}$

(C) $\sqrt{2gh}$

(D) $\sqrt{\dfrac{h}{2g}}$