A 28-year-old lady has put on weight (10 kg over a period of 3 years) and has oLigomenorrhoea followed by amenorrhoea for 8 months. The blood pressure is 160/100 mm of Hg. Which of the following are the most appropriate investigations -
Serum electrolytes
Plasma cortisol
Plasma testosterone and ultrasound evaluation of pelvis
T3, T4 and TSH