A hyperbola having transverse axis of length 1/2 unit is confocal (having same foci) with the ellipse 3x²+4y²=12, then:
a. equation of the hyperbola is x² - y²/15 = 1/16
b. eccenticity of the hyperbola is 4
c. distance between the directrices of the hyperbola is 1/8 unit
d. length of latus ractum of hyperbola is 15/2 unit