Which of these is not a way in which a gm animals contribute to an increased food supply?

a. genetically modified pigs have been engineered, and they produce more lean meat than non-gm pigs.

b. growth hormone genes have been used to make transgenic salmon, which grow much more quickly than wild salmon.

c. cows have increased milk production because they have been injected with hormones made by recombinant bacteria.

d. bacteria are engineered to produce human insulin, which is administered to people with diabetes.