An urn contains 5 green balls, 7 yellow balls and 8 blue balls. Event A is defined as drawing a green ball on the first draw, and event B is defined as drawing a green ball on the second draw. If two balls are drawn from the urn, one after the other and not replaced, what is P(B|A) expressed in simplest form?

A.3/19
B.4/19
C.1/5
D.5/19