Answer to Question 1
C
Answer to Question 2
The diagram should show the two diatomic molecules touching each other so that the two pairs of different atoms are in contact. The drawing may also include lines showing that the bonds in the molecules of the elements are broken and new bonds form between the two different elements:
X---X X X
O---O O O
To illustrate the importance of energy, a heavy line could be used to indicate how hard the impact between X2 and O2 is, using a darker or wider line for a stronger impact. Part of activation energy involves an impact with sufficient energy.