During electrolysis, where do oxidation reactions occur? in the anode of an electrolytic cell in the cathode of an electrolytic cell in the power source of an electrolytic cell in the salt bridge of an electrolytic cell

The correct answer is in the anode of an electrolyte cell.  

An electrolytic cell refers to an electrochemical cell, which mediates a non-spontaneous redox reaction via the use of electrical energy. They are generally used to dissociate the chemical compounds, in a procedure known as electrolysis.  

The electrolytic cells, like galvanic cells, comprises of two half-cells, one is the oxidation half-cell and the other is a reduction half-cell. In the cell, oxidation takes place at the anode, and the reduction occurs at the cathode.