Which one of the following statements is true about 'Diapedesis'?

(1) A shaft of long bone present between two expanded ends

(2) Fall in the level of Albumin of the blood plasma resulting accumulation of fluid in tissues

(3) Penetration of leucocytes from blood capillaries into connective tissue

(4) It is a wide gap on the jaw bone between incisors and premolars

(3) Penetration of leucocytes from blood capillaries into connective tissue