Activation energy of a chemical reaction can be determined by _____________.

Taking ln on both sides give: ln k= -E_A/RT + lnA

The above equation has E_A as activation energy and k as the rate constant.

The equation can be changed to a line equation i.e. y=mx+c, by taking log on both sides.

For two values of k at different temperatures we can get the value of E_A from above Equation.

Thus option (ii) is correct.

Other options do not give an equation or values for a graph that can be plotted to find the value E_A.