Here is a list of metals and their potentials. Pick the ones which are stronger oxidizing agents than hydrogen electrode. You can pick more than one.
Metal 'A' Reduction potential- 3.4
Metal 'D' Oxidation potential- 0.9
Do you remember how to find out reduction potentials from oxidizing potential? You just need to change the sign of the potential.
Let's now convert all potentials to reduction potentials. We will have the following:
A will be 3.4
B will be -2.3
C will be -1.4
D will be 0.9
Now, recollect that an element with a positive reduction potential will have higher oxidizing power as compared to that of Hydrogen. You can always keep Fluorine in mind to remember this. Fluorine has a reduction potential of 2.87 and is the strongest oxidizing agent.
So, we will have A and D as metals with higher oxidizing power that Hydrogen electrode.