Answer:
All of the above
Step-by-step explanation:
All of the above options are examples of how congress oversees the executives such as the president ,a detail example is the recent impeachment of president trump by the congress. Congress carried out investigation which was open, before gathering facts that led to the case of impeachment. Apart from that they have the right to approve presidential appointment and also impeach them ,also they can create regulations and sign them .So all the options above explains the power of congress.