The correct answer is: Only assumption I is implicit.
The statement is an advertisement for X brand of shoes. It says that if you want to follow the footprints of an ideal leader, you should wear X brand of shoes. This does not mean that everyone wants to become an ideal leader. It is possible that some people do not want to become leaders, or that they do not care about being ideal leaders. Therefore, assumption II is not implicit.
However, the statement does imply that wearing X brand of shoes will help you become an ideal leader. This is because the statement says that you should wear X brand of shoes if you want to follow the footprints of an ideal leader. This implies that wearing X brand of shoes will help you become a leader like the one whose footprints you are following. Therefore, assumption I is implicit.
In conclusion, only assumption I is implicit in the statement.