Which of these hormones regulate calcium levels in the body: group of answer choices a) t3 and t4 b) calcitonin and parathyroid hormone c) oxytocin and prolactin d) insulin and glucagon e) melatonin and glucocorticoids.

When it is summer at the south pole, a. the northern hemisphere is tilted toward the sun. b. the southern hemisphere is tilted away from the sun. c. the northern hemisphere is tilted away from the sun. d. both the southern and northern hemispheres are tilted toward the sun.