The correct options are
B Colour of skin and iris of eyes
D Darkening of skin in pregnant women
The intermediate lobe of the pituitary (also called pars intermedia) produces MSH, or melanocyte-stimulating hormone which acts on melanocytes or pigment-producing cells responsible for the colour of our skin and iris of the eyes. MSH gets activated and stimulated during pregnancy and can bring about the darkening of skin in some pregnant women. Melatonin produced from the pineal gland is responsible for the sleep cycle or circadian rhythm. Oxytocin produced by the posterior pituitary causes uterine contraction during child birth.