a) recovered from pituitary glands removed from human cadavers.
Explanation:
The human growth hormone is responsible for growth along with cellular proliferation and reproduction in humans.
The hormone is secreted by the pituitary gland.
Therefore, before the recombinant DNA techniques were available the hormone was isolated from the pituitary glands fo human cadavers.
However, this method was not continued because the extract hormone became a source of infection for diseases such as the Creutzfeldt-Jakob disease.
Therefore, alternatives were looked for and with the advent, in recombinant DNA techniques, the scientist was able to successfully make the recombinant human growth hormone as well.
