3}(a)→(ii),(b)→(iii),(c)→(iv),(d)→(i)
Explaination::
(a) Placenta also acts as an endocrine tissue and produces several hormones like human chorionic gonadotropin (hCG), human placental lactogen (hPL), estrogens, progestogens, etc.
(b) The secondary oocyte forms a new membrane called zona pellucida surrounding it.
(c) The male accessory glands include paired seminal vesicles, a prostate and paired bulbourethral glands. Secretions of these glands constitute the seminal plasma which is rich in fructose, calcium and certain enzymes. he secretions of bulbourethral glands also helps in the lubrication of the penis.
(d) The regions outside the seminiferous tubules called interstitial spaces, contain small blood vessels and interstitial cells or Leydig cells Leydig cells synthesise and secrete testicular hormones called androgens.