Draw the curved arrow mechanism for the conversion of the thioether into the thiochroman product. In the first step, benzyl phenyl thioether is treated with butyl lithium. The resulting compound reacts with styrene oxide (step 2) and then acid (step 3). Catalytic p-toluenesulfonic acid is then added to protonate (step 4) and dehydrate (step 5). This leads to the formation of the electrophile for the electrophilic aromatic substitution (step 6), which is then completed to give the thiochroman product (step 7). When given the choice, draw the arrows that lead to the resonance structures with full octets around each atom other than hydrogen. Draw all atoms, electrons, and charges if necessary on all structures; do not show any inorganic side products or counterions. Reagents needed for each step are provided in the boxes.