3. Jack and Jill go swimming at a place 1 kilometer away from their home, both starting from home at the same time and moving at a constant speed. It is known that Jack's cycling speed is 10 kilometers/hour, and Jill's walking speed is 4 kilometers/hour. Then Jill arrives ( ) minutes later than Jack.
(A) 5
(B) 6
(C) 8
(D) 9
(E) 10
3. D.
$$
\left(\frac{1}{4}-\frac{1}{10}\right) \times 60=9 \text {. }
$$