A vector needs three quantities for its specification . Name the three independent quantities conventionally used to specify the earth's magnetic field ?

Question

$\begin{array}{1 1} \text{(i)Magnetic declination ; (ii) angle of dip ; (iii) Vertical component of earth magnetic field} \\\text{(i)Magnetic declination ; (ii) angle of dip ; (iii) Vertical component of earth magnetic field} \\ \text{(i)Magnetic declination ; (ii) angle of dip ; (iii) horizontal component of earth magnetic field} \\ \text{(i)Magnetic declination ; (ii) angle of dip ; (iii) Vertical component of earth magnetic field} \end{array} $