The length of the latusrectum of an ellipse is 18/5 and eccentricity is 4/5, then equation of the ellipse is . .
a. x²/25 + y²/8 = 1
b. x²/25 + y²/9 = 1
c. x²/25 + y²/16 = 1
d. x²/16 + y²/9 = 1