If p represents the world population in billions and y represents the number of years after 1960, then the world population after 1960 can be closely approximately by the equation P=0.077y+3.04. Which number most closely approximates the predicted population of the world, in billions, in the year 2015?
(A). 7.28 billion
(B). 6.51 billion
(C). 4.20 billion
(D). 14.59 billion