In each reaction box, place the best reagent and conditions from the list below.

This is a two step step reaction as shown below,

Step 1:
           Epoxidation of Alkene:
                                              In first step Cyclohexene is treated with peroxybenzoic acid in the presence of Dichloromethane which results in the formation of epoxide moiety.

Step 2:
           Nucleophillic Substitution Reaction:
                                                                  In second step the epoxide formed is treated with Sodium Methoxide which acts as a nucleophile and attacks the less hindered carbon of epoxide resulting in the formation of final product as shown below.

A) the enthralling of formation for pure element in its standard state is always positivehope this : )

The problem here is that according to aufbau principle before 3d orbital 4s subshell comes.after filling 3p orbital with electrons you have 4 electrons left, you place two in 4s with opposite spin and the other two in 3d in any of its two orbitals of total five orbitals with the same spin.