Correct Option (b) lower levels of blood testosterone
Explanation:
Compared to a bull a bullock is docile because of lower levels of blood testosterone.
A bullock is a castrated bu]l. Bulls are castrated to make them more meek and docile.
Castration is the removal or destruction of one or both testicles and results in sterility, decreased sexual desire and inhibition of secondary sex characteristics. It is performed for the purpose of improving the quality of meat and decreasing the aggressiveness of farm animals; in pet animals it prevents unwanted mating behaviour, reproduction and wandering.
